Beta

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

RAID Trust Issues — Windows Or a Cheap Controller?

Soulskill posted about 5 years ago | from the why-buy-the-mirrored-cow dept.

Data Storage 564

NicApicella writes "My new system has two sparklin' SATA drives which I would like to mirror. After having been burned by a not-so-cheap, dedicated RAID controller, I have been pointed to software RAID solutions. I now stand in front of two choices for setting up my RAID: a Windows 7 RC software RAID or a hardware RAID done by the cheap integrated RAID controller of my motherboard. Based on past experiences, I have decided that only my data is worth saving — that's why the RAID should mirror two disks (FAT32) that are not the boot disk (i.e. do not contain an OS or any fancy stuff). Of course, such a setup should secure my data; should a drive crash, I want the system up and running in no time. Even more importantly, I want any drive and its data to be as safe and portable as possible (that's the reason for choosing FAT32), even if the OS or the controller screw up big time. So, which should I choose? Who should I trust more, Microsoft's Windows 7 or possibly the cheapest RAID controller on the market? Are there other cheap solutions?"

cancel ×

564 comments

Sorry! There are no comments related to the filter you selected.

Just remember the first rule of RAID 0 (0, Offtopic)

Blaze74 (523522) | about 5 years ago | (#28587793)

You lose your data twice as fast!

Re:Just remember the first rule of RAID 0 (-1, Offtopic)

Anonymous Coward | about 5 years ago | (#28587909)

Actually, statistically, its 4 times as fast.

Re:Just remember the first rule of RAID 0 (4, Informative)

Anpheus (908711) | about 5 years ago | (#28587953)

Actually, it depends on the reliability. 95% reliability becomes 90.25% reliability. 50% reliability becomes 25% reliability. 1% reliability becomes 0.01% reliability.

So if your drives are very reliable, it's very slightly less than twice the failure rate. If your drives are not reliable, then it asymptotically approaches an infinitely greater risk of failure.

Statistically speaking. :)

Re:Just remember the first rule of RAID 0 (5, Informative)

Anonymous Coward | about 5 years ago | (#28587951)

That's nice, but the submitter is asking about RAID 1.

Have some FUD with your RAID (5, Funny)

suso (153703) | about 5 years ago | (#28587797)

Do you really want to trust Windows with your data?

Re:Have some FUD with your RAID (-1, Troll)

Anonymous Coward | about 5 years ago | (#28587899)

Yeah, journaling and delayed allocation before a commit in the ext3 and ext4 filesystems are soooo much better.

Re:Have some FUD with your RAID (2, Informative)

lukas84 (912874) | about 5 years ago | (#28588047)

Yeah, blame broken applications on the filesystem. Seems like a good idea.

Re:Have some FUD with your RAID (1)

FranTaylor (164577) | about 5 years ago | (#28588069)

Written in complete ignorance of other linux file systems that do not have these problems...

You are asking the wrong question. (4, Insightful)

mcrbids (148650) | about 5 years ago | (#28587965)

RAID is only marginally valuable. In my experience, for all but the most carefully controlled environments, RAID simply adds complexity, the number of things to go wrong increases, along with the likelyhood of lost data. Do it only if you want the *experience* of running RAID, but don't count on RAID to "save your data".

I've worked as a system administrator for more than a decade, in medium-large scale deployments with good success, (think: servicing thousands of users, hundreds of domain names, tens of thousands of email addresses, etc) so I think I have some useful experience you can benefit from.

IMHO, you most likely to lose data from the following things (in order)

1) Aw sh1tz. "I didn't mean to delete that folder"... or "Whoops! I formatted the wrong drive", "I saved the wrong version of the file!", whatever. Although I *myself* don't have this happen often, it does happen. And even in my case I've lost about as much useful information this way as by drives dying. Users delete stuff all the time, and it's usually my job to bring it back, which is why I perform redundant, historical backups EVERY SINGLE DAY.

2) Malware. Don't minimize this - it's real, and it's why I reply to Parent. You are more likely to lose information from a virus/worm/malware and/or b0rked install of something that hoses your filesystem than by a hard disk crash given stable hardware.

3) Bugs. Filesystems have bugs. So do applications, utilities, anything with software. Strange, unexpected conditions, often caused by bugs in applications can cause data to "disappear", files to get corrupted, filesystems to get corrupted, folders to be incompletely written, etc. This is about as likely to cause lost data as:

4) Hardware failure. This is one of the lowest orders of lost data, although when it happens, it can be one of the most extreme.

Let me say this: RAID 1/5 only PARTIALLY protects you from the last one. Actual, bona-fide backups protect you from all of these. If you care about the data, get backups. If you care about uptimes at great expense, RAID *may* be worth it.

My advice is something most people don't want to hear: for personal use, get backups online for $5/month. Mozy/Carbonite/etc. There are zillion vendors, just Google it. In two years, it will cost you about as much as that 2nd hard drive. It protects you far better than that 2nd hard drive, and it's so automatic that you'll hardly notice it until the moment it actually matters: when you just have discovered that your data is gone.

Re:You are asking the wrong question. (5, Insightful)

InsertWittyNameHere (1438813) | about 5 years ago | (#28588119)

Your 4 points are correct. However, the reason for using RAID is NOT as a backup. RAID != Backup.

RAID is for redundancy and performance increases.

I had a drive die in my NAS a few weeks ago. It took 5 minutes to walk to the server room and plug in a new drive. There's no added complexity for the sysadmin, everything is done automagically by the RAID controller. Losing a server or data for hours while the drive is restored from tape is more expensive and complex.

Re:You are asking the wrong question. (-1, Flamebait)

Anonymous Coward | about 5 years ago | (#28588281)

RAID is for redundancy and performance increases.

Do you mean to tell me that a Redundant Array of Inexpensive/Independent Disks is for redundancy???? NO FUCKING WAY! I don't believe you.

If I was a Wikitard (you know, the ones who can't tell the difference between wikipedia.org and slashdot.org) I'd have to say [Citation Please].

Re:You are asking the wrong question. (2, Insightful)

Anonymous Coward | about 5 years ago | (#28588145)

... you'll hardly notice it until the moment it actually matters: when you just have discovered that your data is gone.

Or until the backup company disappears. I suspect hardware is much more stable than any company providing any online backup.

I'd feel safer by far with an outfit that picks up your physical tapes and can return them as needed. If the company is going belly up, it's a lot harder for them to "lose" a warehouseful of tapes than a bunch of files on rotating memory.

For a private person interested in backup, find a safe, offsite place for your backup. Take at-home backups to work. If you have a small business, take the work tapes home.

Are you crazy? (4, Funny)

FranTaylor (164577) | about 5 years ago | (#28588153)

Do you work for one of these online backup places?

I would sooner trust a WD drive with my valuable data.

Re:You are asking the wrong question. (2, Insightful)

Pentium100 (1240090) | about 5 years ago | (#28588163)

My advice is something most people don't want to hear: for personal use, get backups online for $5/month. Mozy/Carbonite/etc. There are zillion vendors, just Google it. In two years, it will cost you about as much as that 2nd hard drive. It protects you far better than that 2nd hard drive, and it's so automatic that you'll hardly notice it until the moment it actually matters: when you just have discovered that your data is gone.

And is so slow that a LS120 drive reading a 1.44MB floppy would actually be faster. Or a 1x CROM. Or a 16 year old hard drive.

Also, I have to trust that the service and my internet connection will be available when I need to restore my data.

Or I can use RAID... and tapes.

Re:You are asking the wrong question. (4, Interesting)

stfvon007 (632997) | about 5 years ago | (#28588237)

Ive had #4 happen to me. A power supply in my computer failed (a name brand one, not a cheap no name brand) and damaged everything attached to one of the 12v rails. This included both drives of a raid1 set. (ironically all my drives that wernt part of a raid set were completely undamaged) I was later able to recover the data from both drives (both had damaged sections but different areas were damaged on the 2 drives allowing for a complete recovery between the 2 of them)however it goes to show that just having a raid array wont completely protect you from hardware failures.

Re: online backups (4, Insightful)

King_TJ (85913) | about 5 years ago | (#28588245)

Personally, I haven't yet encountered anyone who really got benefit from those personal Internet backup services like Mozy. In regular use, it always seems like the person exceeds their storage allotment or Internet connectivity issues prevent them from recovering what they need, when they need it.

I tend to recommend people buy an inexpensive external USB or firewire drive, leave it attached and assigned as a backup device, and have some software package run a daily backup of all the relevant folders and files they might need to save.

It's great that your data is stored offline and off-site ... but I'm just not sold on most of the implementations for "home use" being as great a solution as they first appear to be. Many of the providers have come and gone over the years, too. What happens when your offline backup company goes under?

Re:You are asking the wrong question. (2, Informative)

MazzThePianoman (996530) | about 5 years ago | (#28588255)

Having run RAID quite a bit myself one must remember having all your drives in one box is always an invitation for trouble since hardware failures on a higher order will likely hit all the drives.

If you want to do online backup get DSL instead of cable internet for the faster upload bandwidth.

Get a backup service with versioning. That way if you or a virus delete something it just doesn't sync the deletion to your backup.

I personally use JungleDisk which uses Amazon S3 storage. You can set the versioning controls and you only pay for the storage/bandwidth you use. My bill averages about $2/mo for several gigs.

Drobo (1)

mveloso (325617) | about 5 years ago | (#28587799)

"I want any drive and its data to be as safe and portable as possible [...] even if the OS or the controller screw up big time."

If the controller screws up and writes crap to your raid, your data is dead. Not sure if your expectations are realistic.

Try a drobo instead.

Seriously? (5, Insightful)

Absolut187 (816431) | about 5 years ago | (#28587807)

You're posting to Slashdot asking whether you should trust Microsoft?
Really?

Re:Seriously? (5, Insightful)

morgan_greywolf (835522) | about 5 years ago | (#28587981)

The article smacks of false dichotomy. There are a number of solutions, not just Windows 7 or a hardware RAID controller.

To begin with, every NT-lineage Windows version ever produced supports software RAID out of the box. Add that to the fact that any major Linux distro today supports software RAID. And so do the *BSDs. And Mac OS X. And Solaris. And probably a bunch of other platforms I can't think of right now.

Hell, you could buy one of these one of these [linksysbycisco.com] and throw the drives in it, connect it to your network switch, and presto -- instant RAID+NAS.

I think we would all like to know why you think Windows 7 is your only option, because if that's what you think, you don't know how mistaken you are.

Re:Seriously? (3, Insightful)

gdshaw (1015745) | about 5 years ago | (#28588113)

The article smacks of false dichotomy. There are a number of solutions, not just Windows 7 or a hardware RAID controller.

Agreed.

As I see it, if you want guaranteed repairability then you basically have two options: enterprise-class hardware with a support contract (and price tag to match), or an Open Source software solution.

Put another way, either you pay someone to take responsibility for fixing it, or you take responsibility yourself. A Microsoft solution doesn't give you enough control to take full responsibility, because you can't be certain that it will be legally or technically possible to recreate your current setup in five years time.

Re:Seriously? (1)

sirsnork (530512) | about 5 years ago | (#28588229)

No where did he suggest he required Windows 7 for RAID, just that thats what he planned to use for this machine. Personally I would just put the second drive in my server and backup my data to that rather than use any of the two options he lists.

Be Careful (0)

Anonymous Coward | about 5 years ago | (#28587811)

Repeat after me: RAID is NOT backup

Re:Be Careful (4, Informative)

tomhudson (43916) | about 5 years ago | (#28588011)

Repeat after me: RAID is NOT backup

... and rsync is your friend.

What RAID is good for:

  • making a bunch of cheap disks you just happen to have lying around look like one larger drive
  • making reads quicker (mirrored disks, and sometimes, but not necessarily, RAID5/6), though you have a performance penalty for writes
  • being able to say "I have a RAID"
  • destroying much larger datasets since "It's safe - I have a RAID"

Better to just throw a disk in an old machine and back up to it regularly.

FAT??? (4, Insightful)

whoever57 (658626) | about 5 years ago | (#28587825)

You data is most important and you plan to use FAT? Good luck with that!

Seriously, though. No RAID solution that is not totally S/W is portable. But do you really need RAID? It sounds like what you need is a good backup solution with frequent backups. Does you data change so much that losing one day's worth of data would be a problem?

Re:FAT??? (2, Informative)

Gription (1006467) | about 5 years ago | (#28587957)

Windows can toast NTFS just as often as FAT. I know Microsoft has trained everyone on the gospel of NTFS but it isn't a big selling point. One difference is that FAT gives you a much larger variety of recovery options. You can have a FAT toasted beyond recognition and still get it back by putting it into a Win 9X box. It is amazingly resilient.

The big problem in this picture is the way that Windows deals with drive errors. It doesn't report them and people commonly discover that one of the drives in a mirrored pair is dead when the second drive dies and leaves them with nothing.

The only way to seriously protect data is Multiple methods of backup and multiple media.
Plus you need to remember that a common first sign of a drive failure is the backups start to fail. If you don't notice it and keep swapping media, pretty soon you have a media set with no backups on it.

Re:FAT??? (1)

rduke15 (721841) | about 5 years ago | (#28588071)

You can have a FAT toasted beyond recognition and still get it back by putting it into a Win 9X box.

Well, if you are able to find a Win95 box, and if you still remember how that works... :-)
(Oh, and it better be a Win95 box with support for FAT32, unless all your partitions are under 2GB)

But I do agree with the rest of your remarks.

Re:FAT??? (0)

Pentium100 (1240090) | about 5 years ago | (#28588207)

FAT filesystem has a second copy of FAT right after the first one. They are updated at the same time, but usually only the first one is used for reading. If the drive develops a bad sector there, you can copy the FAT from its backup.

NTFS has a copy of the first 16 MFT records only. If a bad sector develops inside the original MFT, you can lose up to 64 files. This has happened to me. I am only using NTFS only because I have files bigger than 4GB.

Anyone knows a way to make a backup of the MFT to another disk at the time of write? Then it would be almost the same as with FAT.

Re:FAT??? (5, Informative)

jeffasselin (566598) | about 5 years ago | (#28588221)

No. NTFS is not perfect, but to think FAT is as bad is deluded. I've honestly never seen a HD formatted with NTFS that I couldn't repair with built-in tools, unless it had physical defects, and in such a case ANY file system would have problems. But I've seen so many FAT drives get hosed by little problems, it's not even funny.

Seriously, don't trust your data to a FAT partition - not worth it.

Re:FAT??? (1)

ls671 (1122017) | about 5 years ago | (#28588079)

Agreed, RAID prevents from a drive failure, period. If your controller fails you lose data, if your mother board fails you may loose data, if your memory fails, you may loose data, etc...

As the poster said, I would go first with a proper backup strategy, it is more important in order to secure your data. Then, go with RAID if you evaluate that you still need it. Heck, as the other poster mentioned, you may find out that you do not need RAID anywhere although I always like to add RAID AFTER my strategy is made-up. RAID doesn't really count when you calculate how safe your data is. It's only a "nice to have".

A proper backup strategy involves a second computer that makes everything redundant (memory, controller, MB, etc..) or very expensive business grade devices (+5000 $) with components that are orders of magnitude more reliable than the ones in a cheap PC and that often have those components installed in pairs to insure redundancy within the device !!! Go with a second computer to save.

Hints on a backup solutions:
http://slashdot.org/comments.pl?sid=1277921&cid=28429713&art_pos=37 [slashdot.org]

Re:FAT??? (3, Insightful)

JustinOpinion (1246824) | about 5 years ago | (#28588097)

I'm no expert, but it seems that RAID1 doesn't provide as much safety as some people think, because corrupted data just gets copied twice, so now you have two copies of the corrupted data. Same with accidental deletion--both copies are gone.

If all you want is multiple copies of your data, then really what you want is an automated incremental backup system, that copies your files to a second hard drive, and ideally keeps a few older copies so that if a file gets accidentally deleted or somehow corrupted, you have a chance to go back and find a usable copy. This is what I do on my system: I keep multiple incremental copies from the last few days/weeks/months. It was easy to set-up (in Linux, mind you). Do hourly syncs if necessary.

Also critical, if the poster is truly concerned about never losing data, is to get some kind of offsite backup. Two hard drives don't do you much good when the computer is stolen or your roof leaks. You need to have a way to regularly copy data offsite (ideally automated over the network, or via external hard drive if you're sufficiently disciplined).

RAID has its uses, to be sure. But if the poster is most worried about never losing important user files, then it seems like what he wants is is the multiple-redundancy of backup, not the immediate failover of RAID.

RAID != BACKUP (5, Insightful)

Jave1in (1071792) | about 5 years ago | (#28587827)

RAID is not a backup. Get a backup solution or you'll realize you can be even more frustrated.

Re:RAID != BACKUP (1)

rasper99 (247555) | about 5 years ago | (#28587889)

With two drives you can set up a backup scenario. Put the second drive in an external enclosure and use robocopy on a regular basis. Most data loss is from user error. RAID 0 won't protect you from that. Screw FAT32 and use NTFS. If you need to access it in an emrgency put the drive in an external enclosure.

Re:RAID != BACKUP (1)

darpo (5213) | about 5 years ago | (#28588025)

Exactly what I plan to do to keep my movies/photos/music safe from single hard drive failure: buy two 1 TB external drives, then schedule a robocopy batch file to run once every 24 or 48 hours or so. Rather than mirror stuff in real time, this will allow me to avoid the "oh, shit, I deleted X and it's deleted from the 'backup' drive now too!"

Re:RAID != BACKUP (1)

Pentium100 (1240090) | about 5 years ago | (#28588247)

I know of an even better solution for "oh shit, I deleted a file" moments:
Have the backup software copy all files to the other harddrive. Then once every X hours, have it copy changed files. If a file was deleted on the main hard drive, move it to a separate directory on the backup drive. When that drive is full and you need space for new files, delete the oldest "deleted" files until you have enough free space.

Re:RAID != BACKUP (1)

ls671 (1122017) | about 5 years ago | (#28588177)

A serious backup solution HAS to include incremental backups where you keep ALL previous copies of a file for a given period of time.

Otherwise, you will quickly get screwed in various scenarios. One of them is your main controller failing so slowly that you won't realize that your data is slightly corrupted before it is too late (e.g. you have already overwritten the copy and you no longer possess any non-corrupted copy)

It also needs to have all components redundant. The cheapest way to achieve this is to have a second computer and use the network to do your backups.

I've said it before... (0, Offtopic)

Coppit (2441) | about 5 years ago | (#28587829)

... and I'll say it again: unRAID [lime-technology.com]

Your first problem is Fat32 (4, Informative)

Blakey Rat (99501) | about 5 years ago | (#28587837)

If you want data integrity, use NTFS. Using Fat32 is like saying you want a reliable car, so you're buying a Edsel because they've been around a long time-- it doesn't make sense. Every other OS on earth can read NTFS (if not write it), so it won't affect your portability requirement.

Secondly, before you make any decision regarding Windows 7 RAID, make sure the edition of Windows 7 you want to buy ships with software RAID support before you put all your eggs in that basket-- early betas and RCs of Vista had software RAID enabled, only to have it disabled before release. I've seen no guarantees about Windows 7 software RAID support, and which editions will have it enabled. (If any.)

If you're planning to move to a server OS after Windows 7 expires, I can practically guarantee software RAID will be enabled, but that still doesn't mean you can necessarily upgrade your Windows 7 software RAID array to a Windows Server software RAID array. Do your homework.

Re:Your first problem is Fat32 (0)

0123456 (636235) | about 5 years ago | (#28588033)

If you want data integrity, use NTFS. Using Fat32 is like saying you want a reliable car, so you're buying a Edsel because they've been around a long time-- it doesn't make sense

I've lost far more data on NTFS than FAT.

In fact, I don't think I've ever lost data on FAT without a hardware failure (e.g. bad floppy disk), whereas I've seen Windows delete multi-gigabyte files from NTFS disks after a power-failure. And any blue screen with Firefox open on an NTFS partition would normally delete all my bookmarks.

As I understand it, NTFS only tries to guarantee data consistency, not that your data is actually there; and reformatting the hard drive every time you reboot would achieve that.

RAID is *NOT* backup! (5, Insightful)

pipatron (966506) | about 5 years ago | (#28587843)

You sound like someone that need to be reminded that RAID IS NOT BACKUP! Google for that sentence. All you talk about is saving your data, and RAID will not do that for you. You'd be better off just using the second drive as a backup. RAID will not save you from accidental overwriting of data, corrupt filesystems, broken chipsets, etc. The only thing RAID will save you from is downtime. If you lose that much money on the downtime it takes to recover from a backup, then by all means, use RAID, but don't treat it as a backup solution that will protect your data. That's not what it's made for.

Re:RAID is *NOT* backup! (5, Funny)

Mishotaki (957104) | about 5 years ago | (#28587915)

Wait, are you implying that people should google their question before submitting it to /. ?

Are you insane?

Mod parent up up up (1)

FranTaylor (164577) | about 5 years ago | (#28587969)

The only thing RAID will save you from is a dead drive.

There are infinitely many ways to lose your data, and a dead drive is only one of them.

If you are going to use RAID, you might as well use RAID 0 unless you can't afford the downtime.

If you start talking about data loss, then you just lose, because you should have backups.

Re:Mod parent up up up (1)

Pentium100 (1240090) | about 5 years ago | (#28588261)

RAID1 will protect you from a failed drive (so it's slightly better than having a single drive), while RAID0 is even worse than having a single drive.

Re:RAID is *NOT* backup! (1)

King_TJ (85913) | about 5 years ago | (#28588187)

Technically, you might be correct -- but still, a basic RAID 1 mirror *should* work pretty well as the type of "backup" many of us are seeking.

EG. I have a system that holds and serves all of my movies and video content. Anything I place on it, I intend to keep on it, as a rule. I'm pretty sure I'm not going to lose that data due to a broken chipset - since it's a tried and true piece of hardware. My only real concern is that the drive storing all the data will eventually fail on me. So in this case, doing a RAID mirror of just that data drive is a pretty effective backup solution for me. I guess technically, file system corruption could cause the mirror to become corrupt too and I'd be screwed. But these drives are being read FAR more often than written to. Not a whole lot is going to change on them, generally. And minor corruption can usually be repaired just fine with the usual disk utilities provided with the OS. So yeah, I'm back to the main "risk factor" being a drive failure.

Re:RAID is *NOT* backup! (0)

Anonymous Coward | about 5 years ago | (#28588219)

Nonsense. A simple external drive is a much better solution for your kind of scenario, plus it fulfills the other requirements for backup.

Re:RAID is *NOT* backup! (1)

hitmark (640295) | about 5 years ago | (#28588223)

second drive as backup == raid 1...

Nice choice of filesystem there (0)

Anonymous Coward | about 5 years ago | (#28587845)

FAT32? Are you fucking insane?

Re:Nice choice of filesystem there (1)

tomhudson (43916) | about 5 years ago | (#28588037)

FAT32? Are you fucking insane?

FAT32? You are fucking lame!

There, fixed it for you.

On board all the way!! (1)

splatacaster (653139) | about 5 years ago | (#28587847)

I've been using on board RAID controllers for years and have never had a problem with data loss or crap being written to my drives. A mirror solution is nothing major for a RAID controller to handle. I would never trust windows to software raid anything important.

Re:On board all the way!! (1)

Tmack (593755) | about 5 years ago | (#28587971)

Funny... cause that "onboard" raid is most likely NOT a true raid controller. Sure, there are real raid controllers that get build into mboards, but that generally adds a good $200+ to the cost, and is almost always SCSI. Sata "RAID" cards that cost less than $100 are usually just sata cards with a RAID tag in the bios for certain basic raid-like functions. They do not handle the actual raid IO, the OS (in this case Windows) does the work. A true RAID card will appear as a single device (or multiple LUNs if its handling more than one raid set) to the OS, the individual physical devices are abstracted by the controller, though monitoring apps should be able to give status on the individual drives. For examples of real raid, see 3ware, and notice they arent cheap, mainly because they have their own CPU, ram, bios, etc, basically a SBC just to handle the RAID stuff.

-Tm

Re:On board all the way!! (0)

Anonymous Coward | about 5 years ago | (#28588029)

I have a Gigabyte motherboard with an Intel ICH9R RAID chipset. The OS needs drivers, but can only see one drivel. This applies to the CD based drive diagnostic software too. Only the Intel RAID software and the BIOS can tell that there is more than one drive.

Re:On board all the way!! (3, Informative)

lukas84 (912874) | about 5 years ago | (#28588035)

Fakeraid is software too.

Get a real hardware RAID controller, or don't use RAID. Windows SW RAID or a Fakeraid controller is just plain stupid.

RAID is "High Availability" (0)

Anonymous Coward | about 5 years ago | (#28587851)

Please back up your data. RAID will not save it when your PSU dies and takes both your drives with it.

RAID \neq security. (0)

Anonymous Coward | about 5 years ago | (#28587857)

RAID is not for data security. It only brings speed and/or less downtime in case of a single drive failure, depending on the flavor. One would think everybody would have learned it by now.

Performance of Software RAID = Onboard RAID (0)

Anonymous Coward | about 5 years ago | (#28587863)

Hello,

the only advise I can give you is that performance wise both RAIDS are the same.
In essence the work is done entirely by the CPU by both solutions.

I would not recommend RAID as a backup solution.

Cheers

It's *NOT* hardware raid on your motherboard. (5, Informative)

Zarhan (415465) | about 5 years ago | (#28587867)

These motherboard "raids" are called fakeraids.

All that it is is that it writes the metadata on the disk in specific format so that you can see the raid volumes via BIOS. Note: Only "see" their status - in case you replace one drive, the resync is still done by software and you must boot to operating system. One clue is the fact that in Linux the dmraid package uses exactly same driver for accessing fakeraid-mirrored drives and Linux's own software-raids - device mapper just does a bit of magic at init.

However, if faced with choice of Windows-only or motherboard-raid, I'd go with the motherboard-version, because that's at least supported both by Windows and Linux so in case something goes wrong with your Windows installation you can always pop in Knoppix or some other Linux CD for recovery.

Re:It's *NOT* hardware raid on your motherboard. (0)

Anonymous Coward | about 5 years ago | (#28587989)

Mainboard/BIOS-based RAID is a mixed blessing. If your Mainboard fails, you'll need a similar replacement, if you're lucky, it's sufficient to get something with the same chipset manufacturer (of the SATA controller, that is), if you're not so lucky, you might need the same type or mainboard.

This happened to a colleague, and I tried reading his RAID0 data from linux (Knoppix and Ubuntu) and had to find that the autodetection seemed to work at first glance, but actually could not produce any readable data (i.e. the partitions were unmountable, as was an image copied to an external USB disk, mounted directly or via loopback with various offsets). Luckily it was an Intel-Chipset based RAID, which just happened to work (including booting) with some old P4 box that was rotting away in a corner. The owner of that raid managed to make a copy of the relevant data by himself with that box. The RAID did not work with the replacement mainboard he bought.

Re:It's *NOT* hardware raid on your motherboard. (0)

Anonymous Coward | about 5 years ago | (#28588005)

actually a few server motherboards have real raid cards builtin.

but most of them are fake.

If you really want RAID, either a) use mdadm or LVM (linux)
b) use gmirror (FreeBSD)
c) buy a real raid card (3ware or something - you'll see they'll cost more than 300 dollars normally)

Re:It's *NOT* hardware raid on your motherboard. (5, Informative)

Grishnakh (216268) | about 5 years ago | (#28588123)

DO NOT buy a real RAID card unless you have a pretty good budget for your system, and need the highest performance. The problem with buying a real RAID card is that you need to buy not 1, but 2 or better yet 3 of them, so that you can have spares. If your RAID card dies (and they do, more often than you'd think), the only way you'll be able to access that data, because of the proprietary on-disk storage method used by RAID card vendors, is to have an identical card (with the same firmware version, to be safe). And since hardware is constantly being obsoleted, you need to buy your replacements when you buy your card, not hope they're still available later. It's also a good idea to have spares of the same make and model hard drive, because hardware RAID controllers aren't usually that flexible in allowing you to pair up different sized drives like Linux sofware RAID.

For many purposes, software RAID using Linux is really a much better solution, because the on-disk format is open-source and standardized, so it doesn't matter what hardware you have, you can plug the disks into a different Linux system and you'll be able to read the data with no trouble. The only downside is a slight performance decrease since the CPU has to do all the work, but even then unless the system is heavily loaded, it's still faster than hardware RAID because the hardware RAID cards aren't that fast.

With the giant drives that are now common, I think the best solution, at least for home/desktop systems, is to forget about RAID5/6 altogether and just get a couple of 1-2TB SATA drives and mirror them with software RAID 1 in Linux.

FAT32 is ancient an P.O.S. (0)

Anonymous Coward | about 5 years ago | (#28587873)

For one thing I wouldn't trust FAT32, use a journaled file system for christ's sake if you're concerned about integrity. For Windows stuff NTFS is pretty damn good, Linux has been able to read it just fine for a while so getting to your data if an issue with Windows arises is a non-issue.

Windows + NTFS + external backup (1)

beavis88 (25983) | about 5 years ago | (#28587875)

Cheap RAID controllers suck - at least you can trust Windows to be consistent between installations if need be. External (preferably offsite) backup is also a must! As I'm sure you'll be reminded 1000 times in this thread, RAID is not backup.

Trust Microsoft? (0)

Anonymous Coward | about 5 years ago | (#28587887)

NEVER trust Microsoft with any data that is;

Valuable

Important to you

Cannot be easily reloaded

You're welcome

I don't trust RAID at all (1)

qzzpjs (1224510) | about 5 years ago | (#28587891)

I've already lost a software RAID setup when Linux wouldn't let me put it back together again. A friend of mine also lost his RAID setup on Windows a couple years ago. Also, a mirrored RAID doesn't prevent you from losing data when you accidentally delete that folder of your favorite photos.

I now keep the drives separate and setup a simple nightly batch file to robocopy the files from one drive to the backup directory on the other. It's even better if you can put the second drive in a different PC. This allows me to decide which files are important to me and only do backups of them. That leaves all the rest of the free space on the two drives for more volatile content (stuff I don't care about if I lose). It also gives me time to get a file or directory back if I accidentally remove it. I've done that numerous times when Vista first came out and it didn't move the focus to the right hand side of the explorer window.

RAID is never about protection. (4, Insightful)

MajikJon (661494) | about 5 years ago | (#28587901)

RAID1 serves only one function. Increased uptime. If avoiding having to spend 2 hours restoring from a backup is your primary goal, then RAID1 might make sense for you. Do you have an office full of workers that will all lose productivity if you have a system crash? If so, then RAID may make sense. Any other use of RAID1 is fool's gold. It will not protect your data from a system-level problem. It will not protect your data from corruption (especially not on a FAT32 file system, which was never intended for any partition size above 32GB in the first place). It will not even always protect you from a single drive failure, since the rebuild process in a RAID1 setup often kills the second drive while trying to recover data. As many have said already on the thread, RAID is not backup. Backup needs to be a completely independent device. Unless you have serious uptime considerations, RAID1 should not be part of your backup strategy.

Re:RAID1 is not fool's gold (3, Informative)

alxtoth (914920) | about 5 years ago | (#28588181)

Actually RAID1 is quite good for reading data: it minimizes seek time . Of course, it works fine as long as there are not many writes. For example think analytic databases, cubes, etc. Those are not written to in real time (like the more common transactional databases)

RAID is no substitute for backups (3, Informative)

chrysrobyn (106763) | about 5 years ago | (#28587905)

RAID is no substitute for backups. RAID is very good at propagating errors and problems very quickly, be they software glitches or human errors.

For consumer class storage, weekly / daily backups might be more efficient than investing a lot of effort into live RAID. Since I'm a Mac guy, I see the best answer to this question as Time Machine to a network / USB attached drive -- hourly (configurable for more or less often) differential backups, almost transparent to the user. To my knowledge, Windows has no similar set of software to allow reinstallation to the last hourly backup -- my wife had the misfortune of having to restore a blank drive from her last backup and it was a flawless process that truly left her where she left off less than an hour before the hardware failure. The reinstall wizard just had to ask where the backup was. Casting aside MacOSX advocacy, there is truly no substitute for a good automated backup solution that is regularly tested. I think the best method would use the fewest common components, like a NAS, followed by an external drive with its own power supply. My least favored option would be an internal drive with every single component shared.

Thats not really hardware raid... (1)

Tmack (593755) | about 5 years ago | (#28587919)

most likely its just BIOS headers for some RAID functions. The actual RAID stuff is done by the OS. Almost if not all "SATA RAID" cards that cost less than $100 are just SATA controllers with a thing in the cards bios that says RAID. The OS will still see the individual drives and will have to piece them together. Go search Linux Sata Raid and you will see many, many articles on this. A "true" raid card will show up as a single device to the os (or several LUNs), you will not see the individual physical drives.

If you were doing this with Linux, I would suggest just using md. It works in most cases. For raid1 it mirrors to the point where you can take one drive out and mount it as a non-raid single disk somewhere else. Handy for troubleshooting when ubuntu decides to change uuid drive mappings and thus refuses to rebuild the now broken raid set.....

-Tm

Off site backup and test your restores (2, Insightful)

Nkwe (604125) | about 5 years ago | (#28587931)

The only way to keep your data secure in any reasonable fashion is to make a copy of it and store it offline, off site. Ideally "off site" would be in another building or city, but it at least has to be on something not attached or accessible to your computer.

Without regard to if you use software or hardware RAID or the quality of the RAID system, RAID only protects you from a physical disk failure. If you as a user screw up (delete or change something you didn't want to) or if some software bug screws up for you, or if you have a non-disk related hardware failure (causing a data corrupting machine crash) then you have lost your data -- RAID doesn't help.

Even if you are only trying to protect against disk errors, if the RAID system fails (even expensive quality ones can), or if you don't know and follow the recovery procedures EXACTLY, you can lose all your data.

The only reliable solution is making a copy or a "backup". Backup does not mean making a copy of the data on the same machine. (Whatever took out your RAID might also take out the other non-RAID disk or directory that you put your copy on.) If you are paranoid (or just prudent) your backup should not be a mapped or mounted drive on another machine. (Viruses can write to the network as well.)

And finally... Backups only count if you have tested your restore process.

Your best bet is to buy server grade SATA drives (1)

Kupfernigk (1190345) | about 5 years ago | (#28587933)

I won't try and improve on the comments above, almost all of which I agree with, but I will make one observation. The reason for mirroring is to protect against drive failure. The one time I had a drive failure, mirroring saved the day's data. The best way to protect against drive failure is to buy server grade SATA drives, which are designed for 24/7/365*5 operation, and not cheap PC drives which are designed for 10 hours per day for 3-4 years. Buy server grade SATA drives, mirror them using a hardware controller, back up daily, sleep at night.

Re:Your best bet is to buy server grade SATA drive (1)

Vellmont (569020) | about 5 years ago | (#28588039)


The best way to protect against drive failure is to buy server grade SATA drives, which are designed for 24/7/365*5 operation, and not cheap PC drives which are designed for 10 hours per day for 3-4 years. Buy server grade SATA drives

This is just pure marketing baloney. Do you have any real-world tests that actually back this claim up? I've never used "server-grade" drives, and never will. I've seen "server grade" drives fail in large quantities and "desktop" grade drives last for years running 24/7/365.

The only thing I've seen vary greatly in quality are power supplies. Cheap ones are designed to last a couple years and fail. The more expensive ones higher grade ones tend to be better.

Re:Your best bet is to buy server grade SATA drive (1)

lukas84 (912874) | about 5 years ago | (#28588143)

There are some important differences between server SATA drives and consumer SATA drives - for example the number of retries until an error is reported to the controller. The price difference of course is not really justified by that.

Re:Your best bet is to buy server grade SATA drive (1)

Tmack (593755) | about 5 years ago | (#28588225)

The best way to protect against drive failure is to buy server grade SATA drives, which are designed for 24/7/365*5 operation, and not cheap PC drives which are designed for 10 hours per day for 3-4 years. Buy server grade SATA drives, mirror them using a hardware controller, back up daily, sleep at night.

Err, thats been proven questionable. More specifically, here [eweek.com] is an article from eweek and here [google.com] is the google talk about a large study of drive lifetime characteristics. "Server" drives are just as good as "consumer" drives when it comes to lifetime. The only benefit you get with the more expensive drives is slightly better performance (NCQ, higher rpm, larger buffers, etc). I have several machines at home that run 24x7x365 on the "cheap PC drives" in raid1 pairs (linux md) and a non-raided windoze box, and have had to replace 2 drives out of 12+ over the past 8 years due to failure: I tend to need to upgrade to larger ones before they fail. Even at work we have used the cheaper drives in clusters, next to others running enterprise level drives and found no benefit to the extra cost in most situations.

-Tm

Since You're Just Mirroring ... (1)

SwashbucklingCowboy (727629) | about 5 years ago | (#28587947)

... do it with software. This CPU overhead is minimal for that.

Things like RAID 5 are where you'd be better off with a dedicated controller.

RAID is a high availability feature, not backup (2, Informative)

lukas84 (912874) | about 5 years ago | (#28587961)

Consumer editions of Windows only ever supported Software RAID1. I've made a few experiences with SW RAID1 on WS03, and it's pretty much crap. Linux SW RAID on the other hand worked fairly well.

RAID is not a backup. This is the most important observation. RAID is a high availibility feature. If you lose your RAID array, you shouldn't lose any data. If you do, your backup strategy sucks.

Generally, skip RAID in a consumer setup. RAID is complicated, it's a PITA and especially the low end stuff can do more harm than good. Even expensive stuff can fuck your shit up (I'm looking at you, ServeRAID 8k). Better in invest in a proper backup - to a local harddrive and maybe offsite. Online backups make sense in a home office. For servers, i recommend LTO tapedrives.

Are sure RAID is what you want? (2, Insightful)

rduke15 (721841) | about 5 years ago | (#28587991)

With RAID mirroring, if you overwrite or delete an important file, it's copy on the mirror is immediately overwritten/deleted too, and the file is lost. Wouldn't you rather need a good regular backup?

And as someone pointed out already, FAT is really not a reliable file system. If you are on Windows, use NTFS. It is still portable, having read/write drivers for both Linux and Mac (see this guide [alma.ch] ).

Since the files you want to keep safe appear to be regular files, not system files, any simple file copy mechanism could do. For an easy and simple system, you can use the Windows robocopy.exe tool in a batch file. For a more sophisticated system which can keep older file versions, and can easily be adapted for use over the network, you could try a Windows version of rsync like cwrsync. There are also a few rsync GUI frontends for Windows.

If you decide you really want RAID mirroring and go with the hardware solution, my understanding is that you need a replacement controller in case yours breaks. Since your controller seems to be embedded in the motherboard, you would need a replacement motherboard.

With the Windows software RAID, you are dependent on that software, and have portability only between machines with this Windows 7 software RAID (possibly even only this particular version).

Real RAID is cheap (1)

FranTaylor (164577) | about 5 years ago | (#28588001)

You can buy a real RAID controller for $400-$500 nowadays. If your data is not worth that much...

Re:Real RAID is cheap (4, Interesting)

Grishnakh (216268) | about 5 years ago | (#28588171)

Wrong. You need to buy at least two of these controllers, at the same time, or else when your "real" RAID card dies (and they do), you'll lose all your data unless you can find an identical card (you may even need the exact same firmware version).

Software RAID on Linux is a much better solution, as the underlying hardware doesn't matter. You can mix and match different drive models/sizes (can't do that on HW RAID), and swap the drives to a different system and still read them thanks to the standardized on-disk data format.

Re:Real RAID is (not all that) cheap (1)

Froggie (1154) | about 5 years ago | (#28588189)

You can buy a PC for less than that, and install OpenFiler, or any of a number of free/Free soft-RAID solutions that support Samba.

If you buy a RAID controller, you move the SPOF to the controller rather than the disks (though admittedly it's not got moving parts and should last longer). If you do use a RAID controller card, though, and you want safety, you need a spare RAID controller of the same sort in a drawer somewhere if you expect to get your data back, unless you're sure that the RAID doesn't use a funny on-disk format to store the options it's using.

If the machine is doing RAID and not much else, what are you saving by buying expensive hardware to offload the RAID processing when you already have a mostly idle box sitting there already?

Re:Real RAID is cheap (1)

glitch23 (557124) | about 5 years ago | (#28588233)

I actually have a HighPoint RocketRAID 2300 controller in my system now. It has 4 internal SATA connections using a PCIe interface. I just ordered another one as well from newegg.com. I haven't had any issues with the current one and I've had it for a couple years now. The new one will run a 1.5TB RAID 1 array. This controller supposedly has Linux drivers available for it but mine is in a Windows system so can't verify Linux support. The controller is $119 from newegg and I think it is a good deal. My current controller has a 2 drive RAID 0 and a separate 2 drive RAID 1 array.

Okay. (0)

Anonymous Coward | about 5 years ago | (#28588019)

Using FAT32 means you do not care about your data. Period.

Use NTFS if you're using Windows. Period.

That said - you should be okay with Windows SW RAID. I used it for years in a simple RAID1 two-disk configuration. I've sustained loss of a single disk with no ill effect. I would not, however, recommend doing an upgrade between versions of Windows while doing this. It might work; it should work; but if you go from, say, XP to Vista (Or Windows 7 to Windows Whatevercheesynameisnext) - yeah, that's scare the hell out of me.

Also, as plenty of others have suggested, RAID is not a backup solution. Honestly, it's almost always 'good enough' - but if you're dealing with a simple setup - say, two disks that you've purchased right this second off of NewEgg... You've got to understand, in that sort of situation, if you're one of the unlucky to have purchased two disks from a bad run, RAID won't help you when both disks die a horrible death.

Plan for this. Plan for this even if you take the time to buy disks from different batches. Because at the end of the day, no matter how infintesimal the chances of total failure are, the chance remains. You really need to ask yourself just how important your data really is. Let's face it - it's honestly probably not important enough to go nuts with hourly backups to off-site locations and such. Is it important enough for you to set up, say, an NFS/CIFS/whatever box and sync once a week? Or even slap on an external USB drive and manually copy over your data once a month? Probably! That's still not 'ideal', but it may be 'good enough' in terms of prevention of complete data loss in the event of catastrophic RAID failure.

Oh, and test your backups occasionally. Untested backups, aren't backups.

External eSATA enclusure (2, Informative)

wh1pp3t (1286918) | about 5 years ago | (#28588021)

I would recommend an eSATA RAID enclosure, similar to this [satadrives.com] . Run the newly purchased SATA disks mirrored (RAID-1) in the enclosure. Power up, run backup, power down. Rinse/repeat.

Re:External eSATA enclusure (1)

david.emery (127135) | about 5 years ago | (#28588073)

I'm with him. I have a bunch of external FW800 RAID enclosures (for both SATA and older IDE drives.) Advantages include not using/depending on the computer for RAID drivers (in my case, Mac OS X software RAID), independence from computer failures (e.g. bad power supply), cooling (less hot drives in the case). Disadvantages include performance (unless you have a good eSATA RAID case) and Size, Weight & Power (more than for drives within the computer case).

I've been happy with the enclosures I've bought from Other World Computing (http://www.macsales.com). Although this is -primarily- a Mac dealer, their stuff works on Windows too, and it's high-quality hardware.

If this is not a production web server... (1)

scarolan (644274) | about 5 years ago | (#28588031)

...then you probably don't need RAID. Use NTFS and set up some kind of scheduled backup to the second drive. Or, build a Linux NAS device and run BackupPC (backuppc.sourceforge.net). BackupPC works great for this sort of thing, it can do incremental and full backups of all your data, on the schedule you choose.

Screw RAID (0)

Anonymous Coward | about 5 years ago | (#28588043)

Screw RAID. While it will protect current data in the event of a drive failure it is not excuse to not have good backups. RAID does not protect against overwrites, deletions, filesystem corruption, etc. A good backup, preferably offsite and in multiple snapshots over time, is much much more important.

A word of Caution about RAID 1 & NAS (0)

Anonymous Coward | about 5 years ago | (#28588053)

As has been said many Times RAID != Backup and IMHO RAID 0 SUCKS ROYALLY,
there is a place for other Raid variants. These is a case to be made for using a NAS device for backups.

I use one that is configured to use Raid 1 But there are some devices out there in the market that should be avoided. The NAS I use runs Linux and formats the disks as EXT3 volumes. It fully supports NTFS so windows access is not an issue.

If your Raid Controller imposes a propritary format on the disks rather than using other widely used ones is just plain madness. Why?
If your hardware gives up the ghost you could also end up with major data loss.
If the hardware uses standard disk formats then you can take the drives and recover the data.
For example, the Netgear SC101 is a NAS device that uses a proprietary on disk format. The protocol between the PC and the SC101 is also non standard and IMHO should be avoided at all costs.
Being an old school H/W engineer (I started designing H/W using 74 series Logic) I am suspicious of RAID 5. For m Raid 1+0 is a more recoverable solution.

Whichever RAID solution is chosen, I'd check how the underlying disks are formatted.

RAID != BACKUP (1)

StarWreck (695075) | about 5 years ago | (#28588063)

mirroring with RAID 0 does not take the place of regular backups of data. RAID 0 is for rapid recovery to minimize downtime is MOST instances. Data should still be backed up separately in case of a catastrophic failure.

Re:RAID != BACKUP (1)

Steffan (126616) | about 5 years ago | (#28588173)


mirroring with RAID 0 does not take the place of regular backups of data. RAID 0 is for rapid recovery to minimize downtime is MOST instances. Data should still be backed up separately in case of a catastrophic failure.

RAID 0 != mirroring.

See: RAID 1

RAID is no mystery (1)

borroff (267566) | about 5 years ago | (#28588077)

They've been doing RAID in hardware for quite some time now - the hardware may fail, but I don't think it'll mess up your data. Think of it this way: The hardware controller only has to do one thing, which is to serve RAID. The OS, on the other hand, has to do a bunch of things, any one of which could go bad and kill your RAID.

I've done both hardware and software RAID-1 in the past, with Windows, Solaris, OS X, and Linux. For Windows, go for the hardware RAID.

Re:RAID is no mystery (1)

borroff (267566) | about 5 years ago | (#28588121)

I just re-read your question (RTFA). FAT32 is your first mistake. RAID instead of backup is your second. Your data is more at risk from a users' actions than from hardware failure (given a burn-in period). Figure out how much work you can afford to lose, then use that to create a schedule to backup to some other media, be it disk or tape, that you can take offline.

You may not have a choice (0)

Anonymous Coward | about 5 years ago | (#28588085)

Software RAID 1 is only supported on server versions of Windows, and I haven't read anything on Windows 7 that mentioned any changes in that regard.

I don't really trust cheap motherboard RAID controllers, but I'd use them for RAID 1, since each drive has a complete copy of the data. For any sort of redundant striping (RAID 5/6/10/50), I would use software RAID or a real hardware RAID controller.

Kudos. (5, Funny)

denttford (579202) | about 5 years ago | (#28588093)

"Safe" FAT32, cheap RAID, RAID implied as backup, Microsoft.

Nice job, you successfully trolled the /. frontpage.

None of the above (0)

Anonymous Coward | about 5 years ago | (#28588111)

You'd be better off putting the second drive in an enclosure and using it for off site backups. That way when the main drive fails at least you have a backup to recover from. RAID 1 will just fail on you when you come to re-build the array and you are making work for yourself before then. RAID is good for uptime and throughput but nothing else.

why is this slashdot front page? (0)

Anonymous Coward | about 5 years ago | (#28588131)

I don't normally comment but WTF is this doing on front-page of slashdot? As for the question, go with a dedicated hardware based raid controller. Just cause you gut burned once doesn't mean that the dedicated controllers are bad. I can guarantee the software RAID via windows is worse because of Dynamic Disk partitioning is slow and its not swappable between platforms for recovery. Also FAT32 should never be used outside a USB flash drive or similar device; its terrible for handling large files over 2GB and it inflates the size of small files. If your data really is important go with NTFS for windows or EXT3 (other?) for Linux; it should not be an un-common file system as rare file systems dont plug easily into other computers for data recovery. I've tried several different motherboard integrated raid controllers (intel, nvidea, amd) and all were either unstable which caused disk synchronization issues, slow, or had very little bios-level controls. The little Promise and Highpoint raid controllers aren't what they used to be in quality and performance. Get yourself a 3ware PCIe 14x controller for SATA/SAS controller which costs $$ but you'll thank youself for the investment. Its fast, stable, handles 4 x 2TB SATAII hard drives and is bootable for Windows / Linux. The only time I've ever trusted a software based RAID was with Linux EXT3 based software raid. The actual hard disks are standard EXT3 (not some funky format) which means I can remove any 1 disk and plug it directly into another Linux system without having to do anything special to read the data. That the linux software raid is still very fast, easy to administer, and is most importantly stable. For the super cheapo just don't use raid and get yourself an external eSATA drive and do regular backups. Regular backups aren't the same as RAID but its better than Windows Dynamic Disk any day and still protects your data; oh and its fast and as reliable as you do backups.

Are we talking Pr0n or Tax Receipts here? (2, Interesting)

Cordath (581672) | about 5 years ago | (#28588149)

If you're just want a convenient backup of your music collection, porn collection, musical pr0n collection, or your pr0n musical collection then RAID is not a horrible thing. However, if you're backing up important files, like the only existing scans of the now-burned dossiers William Mark Felt [wikipedia.org] left you, then you should not stop at RAID. Statistically speaking, if something happens to one HD in your machine, like a massive power surge or being confiscated by tight-lipped men in black suits and black sunglasses, it has a pretty high probability of happening to the other HD. Offsite backups are, therefore, prudent. Leaving a HD in a box at the bank and giving the key to your lawyer is one of the safer things you can do, but not terribly convenient. There are a variety of online backup services available that are decent. I'll leave it to others to speculate on which ones are least likely to be fronts for the NSA. If you feel that your data might actually be interesting to more than one human being on Earth, don't forget to encrypt it. (Be honest with yourself. You are posting to /. after all.) I'm rather fond of emailing moderate risk files to my gmail account. (Stupid, I know, but very low effort and they're available anywhere you feel safe enough to check your email.)

As for Motherboard RAID chipsets... Keep in mind that your motherboard has a non-zero probability of frying, having it's caps go bad, being peed on by irate government agents, etc.. I once had a RAID 0 array that was hooked up to one of those things. After the Mobo died I had to do without letters K through P of my Japanese horror-comedy-porno-game-show collection until I was able to find a used computer with the same RAID chipset. (I don't know if it's changed, but at the time each different RAID chipset made RAID 0 arrays that were not compatible with anything else on this lump of rock.) If data portability rather than performance is a priority for you, my advice would be to avoid hardware RAID entirely.

don't use RC as your production box (1)

PastorPete (1500975) | about 5 years ago | (#28588165)

you shouldn't be using release candidate software as your production box. everything else become academic after that. when Windows 7 is released to the general public in a production version and you upgrade, you're going to need to wipe your RC version. so just don't do it.

NTFS + External USB disk + MS SyncToy (1)

flyingfsck (986395) | about 5 years ago | (#28588185)

There are a number of reasons why not to use FAT: 1. Unreliable 2. Doesn't support large files 3. Doesn't support advanced permissions Since you are running Windows, use NTFS, an external USB drive for backup (also NTFS) and the free Microsoft SyncToy to make periodic backups to the external drive.

linux software raid is as portable as it gets (0)

Anonymous Coward | about 5 years ago | (#28588195)

Linux software RAID is about as portable as it gets. It is totally independent of software vendors and/or hardware vendors. It also gives you great flexibility with file systems and growth. You can even make a RAID 5 array and just slap another drive in later to extend your space, something which other solutions don't let you do.

RAID IS NOT A BACKUP SOLUTION! (1)

xous (1009057) | about 5 years ago | (#28588209)

RAID is not a backup solution.

You should be using mirroring in addition to frequent backups.

RAID does not protect against (accidental) deletion, file system corruption, or user stupidity.

RAID (2, Informative)

mysidia (191772) | about 5 years ago | (#28588297)

You're in a special situation using Windows 7 RC. So despite the below, you're especially at risk to the possibility of a new (but not yet discovered) bug in Windows release-candidate software, don't use Windows or other RAID capabilities for your "data protection", use backups. Use RAID mirroring for improved performance or to reduce the probability of downtime occuring, and allow for rapid recovery from common drive failure scenarios.

RAID controllers (Software or Hardware), all suffer from various scenarios where the entire array can fail, and data recovery becomes so hard that it may as well be lost. 90% of the bits may be there redundantly, but you can't get to them for one reason or another. Also, RAID will not protect against system compromise, software data corruption, accidental deletion, or any type of volume corruption that occurs as a result of software running on the system.

Don't pick FAT over NTFS on the basis of portability between systems, if reliability is more important, the NTFS filesystem uses a technique called journalling which makes data corruption less likely after a system crash, eg power failure. NTFS _can_ be read by common solutions, if you need to recover data. Recent Knoppix CDs and various rescue disks can read NTFS, and the filesystem checking tools available for NTFS filesystems are better. FAT is more susceptible to certain failures, including excessive fragmentation leading to poor performance.

Research what type of RAID solution your integrated hardware really is. If it is hostraid, or fakeraid, that requires Windows drivers to implement RAID, then don't use that, avoid like the plague as it's SOFTWARE RAID, even though the software is running inside a driver provided by the controller vendor and A FEW functions may be offloaded to hardware, the main RAID code is still running in software, which is bad, mmmkay?

You can often detect this in that there will be Windows only drivers, or the product will be labelled a hostraid solution, but each of the major drive controller/RAID chip manufacturers has a different name for their ultra low-end solution that isn't really hardware RAID, but has hardware offload of just some functions (checksumming, mainly).

(Fakeraid/Hostraid adapters that require special drivers in the guest OS to implement RAID, also generally suffer from the RAID5 write hole if you utilize RAID5. And RAID code may be more susceptible to certain problems, when it isn't running on card firmware.)

I would actually favor implementing RAID in Windows over that. However, there is hardly any point of doing this, except if you are mirroring your boot drive, or you need RAID for improved performance (e.g. You could use RAID1 for all drives to improve read speeds, RAID1+0 to improve both read and write speeds, or RAID5 for redundancy and scalability at the cost of slower write speeds and a read speed penalty).

I mean that: since you aren't mirroring your boot drive, there is little point of utilizing RAID in your case. One of the most performance-effecting files on your disks is the page file on the boot drive. If you were utilizing RAID for improved performance, you should definitely want to maximize read and write speeds to the boot drive.

If your non-redundant boot drive crashes, your system will be down and need to be re-installed on a new system drive. You may as well just pre-image a backup drive with your system, keep a continuous backup on another machine, and in the event of a failure, pop in the backup HD, and start restoring continuous data from backup, to bring your 'spare' up-to-date.

This will probably even be faster, as an OS reinstall and re-up of Windows is not required

Second, your RAID controller can fail, make sure you have a plan. That would mean either two identical controllers with the exact same firmware version, or you use a very common controller that you are CERTAIN you can easily buy another of, if the first one fails.

ï Should your RAID controller burn up or otherwise fail, you won't be able to get at your data, at least not easily, until you get a new one. That's because most types of RAID controller will write proprietary header blocks to your disks that are specific to the controller involved.

(It might be possible to extract data, but it's a tossup, not trivial thing)

RAID1 is preferable, if you will go through extreme lengths for data recovery, as at the end of the day, your data's redundant copies are most likely recorded directly. If you use RAID5, the bytes on the surfaces of disks are further encoded using the RAID5 parity algorithm.

If you utilize RAID0 there is no redundancy, and should one drive partially fail (e.g. with unrecoverable read errors on some sectors, few bad sectors, or a small portion of drive surface scratched), data recovery is even harder than a single standalone drive partially failing.

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?
or Connect with...

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>