×

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!

Comments

top

Pollution In China Could Be Driving Freak Weather In US

rwa2 Re:Or it could be (156 comments)

I bet if you got any typical Climate Scientists drunk and just partied with them, it would eventually spill out that they have no fucking clue what they are doing.

My father-in-law is actually a "climate scientist", or at least a high-ranking mathematician for GSFC. He's Russian, so he and his friends actually care little about environmentalism and pollution and littering and social responsibility and other stuff like that, even though they are at times the outdoorsy-type who do like to go hiking and camping in large groups and playing and singing music loudly to the annoyance of nearby campers.

What he does care about is math, and the mathematical models for tuning and interpreting satellite LIDAR and other instruments, and if you're doing the math wrong he will yell at you condescendingly. He does get annoyed, however, at all of the politics that are getting in the way of the schedules and funding for his next satellite launch.

A lot of his work involves collecting data on cloud and vegetation cover, and how that affects the energy balance. Pollution and airborne aerosols often seed clouds and serve to reflect solar energy back into space, so being able to measure the effects of that would give us a better picture of how fossil fuel consumption does help "self-regulate" greenhouse gas effects. It probably doesn't help that one of his main projects these days, DSCVR, is essentially known as "Goresat" within GSFC. But essentially these scientists are much too wrapped up in gathering data and facts properly to worry about pushing any social agenda... to them, any form of politicking is just a waste of time and energy and schedule on both sides. There's SCIENCE to be done! :P

2 days ago
top

Ask Slashdot: Which NoSQL Database for New Project?

rwa2 Redis (1 comments)

I've been hearing lots of good stuff about http://redis.io/ . We're using it as a small but integral piece of our Logstash / Kibana farm, and it's probably the most reliable component of that mess. Open source, lots of object oriented data formats and language apis, quite fast. That said, I haven't done much with it personally.

I'm pretty much the Couchbase guy atm, and keeping it running has been somewhat painful (mostly because of pathological clients sending it way too many writes, or apps using the old ASCII memcached protocol instead of the newer resilient smart client APIs). However, Couchbase is hands down one of the fastest, and also has some interesting Couchbase-lite libraries that can automagically keep json sync'd between your mobile client apps and the backend couchbase server farms. It's also quite easy to use the advanced replication and data center sync options, provided you don't run into any bugs that cause it to break. So if you have the time and resources to test, monitor, and care for Couchbase, it's certainly worth a shake.

about two weeks ago
top

Your Car Will Tell You How To Hit the Next Green Light

rwa2 Re:In a society that has destroyed all adventure (364 comments)

the only adventure left is to destroy society.

Well, this is just the first step towards eliminating stoplights entirely. Once all the cars can talk to each other and pace themselves, everyone can just coast through open intersections and weave between each other effortlessly. You'll never have to use your brakes again except to come to a complete stop at your destination!

If that's not an adventure, I don't know what is.

about two weeks ago
top

UN Report: Climate Changes Overwhelming

rwa2 Re:Projections (987 comments)

Nah, that can't be the point of it... no one (nation, not person) would actually listen (or more importantly, act by passing and enforcing meaningful regulations) based on reports or projections.

It's pretty much a given that people are going to have to die on a fairly large scale for anyone to come to their senses.

These reports are pretty much just a CYA so the agencies don't get sued for not predicting this stuff later.

The people that matter, like insurance brokers, have already acted to stop covering low-lying areas. Hasn't stopped people from building on that property anyway, like those neighborhoods in Oso buried in the landslide.

So just prepare to set your thresholds by how many lives are enough to take action, and have your catalog of bandaids ready when nations are finally ready to #panicbuy.

about two weeks ago
top

Ask Slashdot: What Do You Consider Elegant Code?

rwa2 Quine-Relay (373 comments)

To me, elegance at code level means succinct and readable code. Optimizing for performance usually comes at a lower level of readability.

Therefore, first write the code in the most elegant way.

Then, write an optimizer that optimizes that code. Of course, the optimizer itself should be elegant, but it need not be efficient.

For some reason, your comment reminds me of this:
https://github.com/mame/quine-...

Code doesn't get much more beautiful than:
https://github.com/mame/quine-...

about three weeks ago
top

Goodyear's New State-of-the-Art Airship Makes Its First Flight

rwa2 Re:nitpicking nomenclature (66 comments)

Oh, come on, say it with me...

"Semi-rigid derigible"

Say it again!

Say it three times fast!

Try to keep a straight face!

about a month ago
top

Ask Slashdot: Linux For Grandma?

rwa2 Linux Mint on a USB stick (287 comments)

http://www.pendrivelinux.com/

Running a recent version of Linux Mint with the MATE desktop
http://linuxmint.com/

Create a big 4GB casper file on the USB stick.

Have it mount the existing hard disk and create shortcuts so they can get to their photos and stuff.
Maybe put on http://www.playonlinux.com/en/ to help get some of the old Windows software working under Wine

Bring a new stick with you over the holidays with upgrades.

They may or may not use it (they can just remove the USB stick and reboot to go back to their old getup), but at least you feel good that you've done "your part" without spending more than a few hours downloading and twiddling while you're there, and they don't go running off to all their friends complaining about how you came and now their computer is all different.

about a month ago
top

It's True: Some People Just Don't Like Music

rwa2 Re:Ringing in my Ears (268 comments)

Meh, I get that when I start hyperventilating. You should just have your blood pressure checked.

I kinda thought that I didn't like music either, then some slashdot post recommended one of the streams at http://somafm.com/ . Since then I've actually spent some money on an album or two. Though I still don't have an "entertainment" budget set aside to speak of.

Also want to put in a plug for http://sleepbot.com/ambience/b... , which is generally "not music", at least not as you know it.

about a month and a half ago
top

Ouya CEO Talks Console's Tough First Year, and Ambitious "Ouya Everywhere" Plan

rwa2 Re:Ouya just isn't compelling (134 comments)

There will be a four-digit user along any moment to put us in our place.

Yep, telling us about Hot Grits, Natalie Portman and $$$ Profit.

No, you're thinking of the 3-digit UIDs.

about a month and a half ago
top

The Rescue Plan That Could Have Saved Space Shuttle Columbia

rwa2 Re:However.. (247 comments)

Seems like they could have launched some kind of lifeboat or three up to dock with them within 30 days.
How long would it have taken the Russians to prep a Proton rocket to deliver unmanned Soyuz capsules (and an airlock adapter) to them?

Eh, it would have looked bad to ask for help from the Russians. Nevermind.

http://www.nasaspaceflight.com...
http://historicspacecraft.com/...

about 2 months ago
top

Do We Really Have a Shortage of STEM Workers?

rwa2 Re:I thought this had been settled long ago. (491 comments)

Mod parent up!

This is exactly what is going on. There isn't a shortage of STEM workers at all. There is a shortage of STEM workers willing to work for minimum wage. What companies want is H1-B factories. Cheap foreign labor. I don't know who will buy their products when nobody has a high enough paying job to afford them though.

Eh, wealth is power... concentrating the wealth into the hands of a few means they get to tell everyone else what to do.

But wealth is also mostly on paper... the people who do the work and generate the productivity should still be able to get by once everyone realizes all that paper wealth/power is imaginary (or more likely, collapses under its own accord from all of the wealth multiplication schemes / scams).

But in the near term, globalization will sweep away the power of nations to be replaced with corporate multinationals. Which might be OK, since the concept of national sovereignty is merely some sort of institutionalized quasi-racism anyway.

http://economixcomix.com/home/...

about 2 months ago
top

Ask Slashdot: When Is a Better Career Opportunity Worth a Pay Cut?

rwa2 Re:I just went through this... (263 comments)

Good story. I essentially did this too about 2 years ago, under similar conditions.

Grew up in the DC area most of my life, and had some good jobs there working for various "Beltway Bandit" engineering firms, with the security clearance, unlimited overtime, occasional 2 week travel... it felt like a scam. Despite all of the perks, I was certain I didn't want to live that way the rest of my life. Plus, vitamin D deficiency from working in SCIFs all day was starting to eat my bones. But I saved up enough money to move the family out to the west coast to finally live a little.

It was a pretty substantial pay cut, but the cost of living out here West ended up being lower too. We now rent a house 3x the size of our old 2br condo. We're on a strict budget now that the wife stays home to tend to the kids, but everyone is a lot less stressed and doing better in school, and we eat better now than when we hit restaurants half the time. People out here are workaholics in comparison to DC ("Southern Efficiency; Northern Charm"). But they play much harder too. First week at the new job and my boss hands me a beer from his mini-fridge, which would never happen back East. And we have a whole bevy of new places to explore on weekends after having exhausted most of our old haunts.

So yeah, "follow your heart", but be sure to think it through... you don't want to be changing jobs every year, but you don't want to stagnate at one place for more than 5-10 years without growth either. See the good parts of whatever you end up doing, be prepared to make the sacrifices you're willing to take to make the changes you want in your life, and consider what is your "path of least regret".

about 2 months ago
top

Oklahoma Schools Required To Teach Students Personal Finance

rwa2 Re:Rules for kids (304 comments)

Good advices!

1. I'd say it's possible to get ahead using a credit card, but you need to be very disciplined. The agreements are very much structured as a deal with the devil, as soon as you get behind one payment they start charging you as many fees and interest charges as they can. That said, you can win by:

Getting a card with 0% APR, and paying off the balance in full each month.

ALWAYS paying your balance off in full every month before the due date. Do not carry a balance, since this means they start charging you fees.

If you miss a payment, you LOSE. Minimize damage by paying off your entire balance completely (including stuff that hasn't hit your statement yet) and stop using the card until they stop charging you fees and you return in good standing. This may take 2-3 billing cycles. They will continue to charge you fees for several months, along with interest based on your "average daily balance" (i.e. not the balance of $0 if you pay it off before your statement date comes around). If it's your first time paying late, MAYBE you can give them a phone call and have all the fees waived once.

Set up automatic payments from your savings/checking account, so you never miss a payment

Make sure you always maintain enough money in your savings/checking account so you can completely pay off all the balances on all your credit cards and still have enough to live for 3-6 months. This probably takes the most discipline, since it means you probably want to live on a strict budget until you hit that number.

Profit! Pay your credit card statements as late as possible, but no later (I usually schedule them about a week before the due date). If done right, you essentially end up floating the money you spend with your credit cards for 1-2 months... meaning the money you spend will stay in your bank account (earning interest, however meager it is these days). And if you have good credit score, you can probably get some percentage rewards on your credit card purchases (1% - 5% is common).

Share the wealth - of course, cashback from the credit card essentially means the merchants you frequent are paying you a percentage whenever they run your credit card (or, er, the credit card company is giving you a small cut of what they charge the merchant for transactions). So if there's a merchant or restaurant you like, consider paying cash, especially when tipping waitstaff (who might then be able to go on and, er, underreport their tips to reduce their tax burden, which is illegal but I'm sure it happens and doesn't really have anything to do with you other than they will love you for it).

2. Yes! Don't be afraid to be your own accountant, tax forms are all written towards an 8th grade comprehension level (ha ha). But really, tax incentives are there to help shape your behavior and a lot of it is actually very level-headed for something that comes out of government - there are little rewards you can score at the end of the year for improving your energy efficiency, supporting good charities (more money donated to stuff you actually want to support means slightly less tax dollars for congress to throw at things you don't like). But by all means use an online service like taxact or turbotax to take the liability off of you if there's an honest mistake that slips through.

3. Yeah, life insurance doesn't work the same way it does in the Game of Life for some reason. Usually if you can snag some from your employer for little to no contribution, that's worthwhile to make sure your family has enough money to bury you if you die, and keep the house and family car running until they can cozy up with another breadwinnar.

4. Compound interest might be the only useful financial advice you can get out of a high school education these days. But they still don't really give you a lot of rules of thumb that fall out of that, such as:

Inflation means everyone's money depreciates about 3% each year. If your bank account's interest rate is less than that, you're not going to be living off of interest income :P

A typical 30-year mortgage means you'll probably pay the bank back twice the amount of the original loan.

Don't buy a house that costs more than 3x your annual income.

5. Rings true, just pick the index fund with the lowest admin fees. You're in it for the long run, and lots of smart investors have repeatably demonstrated that index funds, even fairly random ones, tend to outperform "managed" mutual funds over the long term.

6. Yes, don't turn down free money! In the same vein, you can help teach your kids to save money by setting up an e.g. a 50% parent-matching contribution for whatever pocket or present money they put in their bank account instead of blowing on candy and toys.

about 2 months ago
top

Book Review: Sudo Mastery: User Access Control For Real People

rwa2 Re:144 pages (83 comments)

Oh, just make it more like Windows and use
* ALL=ALL:NOPASSWD
already! :-D

Then you can set up passwordless ssh with no passphrase to all your systems do stuff like
for H in `cat myhosts.txt` ; do ssh -qt $H "sudo rm -rf /" > $H.txt & done

about 2 months ago
top

Who's On WhatsApp, and Why?

rwa2 Re:Last week. (280 comments)

Yeah, the NPR reporting on this last week pretty much indicated that WhatsApp is extremely popular in the developing countries (BRIC, etc.). Facebook bought their user base, and are probably not all that interested in their app, so none of us should really be interested in it either.

US has always been weird with respect to SMS, what with them charging extra for low-priority data packets that essentially piggyback on the cell tower control packets "for free". But chalk that up to the "ingenuity" of Amurrican marketing and productization.

For my part, I just use the Google Voice app to do SMS on my existing data plan. But I never got into doing SMS via Twitter, which is probably closer to whatever it is that WhatsApp does.

Another thing the NPR coverage touched on was the $1 / year paid subscription model that WhatsApp uses, and that the Russian (Ukrainian?) developer is pretty against any kind of embedded advertising, so it'll be interesting to see what Facebook does with this. I'm frankly kinda surprised I haven't read much coverage about this on any of the tech news sites, it's really weird getting deeper coverage about $random_software on mainstream broadcast radio, compared to what would have made the news just a decade or so ago.

about 2 months ago
top

Why Is US Broadband So Slow?

rwa2 Re:How can the situation impact real estate prices (513 comments)

So I don't really understand why utility quality doesn't seem to affect realty prices. Maybe if Zillow and Craigslist started including broadband rankings from broadbandreports.com for homes and rentals alongside listings, we'd get somewhere. Thus far, it doesn't seem to appear on the radar, somewhere far beyond "school rankings in standardized testing" and even "price of garbage collection".

Of course, then the internet availability score might start to have some impact on assessments used to determine property taxes, which could start having unintended consequences. But I'm pretty surprised thus far that more people don't really shop for residences by FTTP availability.

about 2 months ago
top

Is Google Making the Digital Divide Worse?

rwa2 Re:This is the most retarded astroturf post ever (259 comments)

Amen to that. If you look at the Google Fiber Cities plan at https://fiber.google.com/newci... , you can more or less see that Google Fiber is trying to avoid population centers where the internet is already well developed (DC-NYC-BOS corridor, LA, Chicago, Seattle, Houston) and primarily concentrating in "up-n-coming" low-cost southern tech centers, which already typically get lower marks for education.

So if anything, Google Fiber appears to be trying to bring the poors up rather than help the richers widen the gap.

about 2 months ago
top

Sony's Favorite Gadget Is Kinect

rwa2 Re:It's also hated by most players. (222 comments)

So I don't really game console, but I hear Child of Eden was maybe the only game that used Kinect right, and it's pretty much an abstract musical game that lets you shoot lasers from your hands.

I did get a PS2 and a nice wheel to play GT4... and now that the PS4 is out I might shell out for a used PS3 so I can play GT6. But yeah... Playstation tends to have a few really good exclusive titles, while XBox tends to just be a cheaper and easier to use (well, OK, "dumbed-down") gaming PC. But I already have a gaming PC, so.

Which is a shame, since I used to work next to the Forza devs, and have to admit the 3-screen setup with a good wheel / shifter / pedals they have in their lobby feels awesome. But XBox never supported the somewhat-affordable Logitech G25 / G27 wheel, and I'm not going to shell out 2 - 3x as much for the slightly nicer German racing wheel / shifter that does work with an XBox or three that I don't have.

about 2 months ago

Submissions

rwa2 hasn't submitted any stories.

Journals

top

Android 4.0 ICS on ViewSonic G-Tablet using TeamDRH

rwa2 rwa2 writes  |  about 2 years ago So VeganTab 7.1.0 (Android 2.3 Gingerbread) still appears to provide better app compatibility and performance, but it looks like the Android 4.0-based TeamDRH ROM is getting close in functionality!
I just installed the Beta 1.1 release, and it's making my G-Tablet run real nice. They ship with a 1.2 Ghz overclock option, and the Quadrant scores are better now, in between the Samsung Nexus and Samsung Galaxy. (The VeganTab ROM blew away both of them with a 1.4Ghz overclock).
Still a few issues I've reported:

  • Had to kill DSPManager to get audio working:
    mount -o remount,rw /system
    mv /system/app/DSPManager.apk /system/app/DSPManager.disabled
    reboot
  • Had to uninstall a bunch of background apps / widgets to free up enough RAM for everything to run smoothly. ICS really expects to have 1GB of RAM, so need to lose some weight to get good performance on 512MB :-/ Use an app like "OS Monitor" to see what's running and sort by memory usage.
  • My main goal is to get one of the full Linux distros installed in a chroot, but the TeamDRH kernel doesn't have loop block devices enabled.
  • A few apps don't run yet, like "Leo's RC Simulator", but I suspect they haven't ported to ICS yet.
  • ICS changed the way the internal sdcard can be shared with the PC, and I can't get the new way working :-P So now it's kinda a pain to transfer large files / backups.

But aside from that, I'm rocking out.

top

Running commands on many remote hosts using ssh and xargs

rwa2 rwa2 writes  |  more than 3 years ago

There are a few different ways to run commands on groups or clusters of remote nodes, depending upon how complex the command.

Assuming your machines are named "node01" - "node10" :

# Run a command in parallel on all remote nodes
# results come back in random order as they are received.
pdsh â"w "node[01-22]" df

# pdsh allows some more complex listings of hosts
pdsh â"w "node04,node[06-09]" reboot

# Run a command sequentially on all remote nodes
# slow, but results come back in order
seq â"w 1 22 | xargs â"I '{}' ssh node'{}' df

# Run a command in parallel on all remote nodes without pdsh
seq â"w 1 22 | xargs â"P 22 â"I '{}' ssh node'{}' df

# Run a command in parallel needing pipes on the remote host
# Otherwise, pipes are processed locally
seq â"w 1 22 | xargs â"P 22 â"I '{}' ssh node'{}' \
"ps afx > \`hostname\`.txt"

# Run a command in parallel needing root
# sudo requires a tty, hence we pop up xterm windows
seq â"w 1 22 | xargs â"P 22 â"I '{}' xterm â"e \
"ssh -t node'{}' sudo gdm-restart"

# Run a command in parallel needing root and pipes on the remote host
seq â"w 1 22 | xargs â"P 22 â"I '{}' xterm â"e \
"ssh -t node'{}' sudo bash â"c \"echo 3 > /proc/sys/vm/drop_caches\""

top

Using readahead to speed up disk loading times of any application

rwa2 rwa2 writes  |  more than 3 years ago

Here's a way to get a list of files read by any application, so you can use readahead to preload those files optimally from disk:

CMD=firefox
strace -fe open $CMD 2>&1 | sed 's/.*open("\(.*\)".*/\1/' > $CMD.preload

# you can sift through that $CMD.preload file to look for things that don't belong

readahead $CMD.preload # preloads all those files into cache

time $CMD # should now start quite a bit faster, without much disk activity

## to clear disk cache as root (useful for testing / benchmarking)
echo 3 > /proc/sys/vm/drop_caches

If it works, you might want to append the contents of the .preload files for your commonly-used apps to /etc/readahead.d/default.later , so they are automatically loaded on startup (RAM size permitting)

top

tangoGPS - alternative to Google Maps Mobile on Linux devices

rwa2 rwa2 writes  |  more than 4 years ago

So back when I had a Blackberry for work, the one app I really got addicted to was Google Maps Mobile. I basically stopped ever planning for travels. I would hop in the car or get off an airplane, think "now what?" and whip out the device and within a minute or two have directions to some place I've never been to before or a list of the nearest restaurants with a smattering of reviews.

Unfortunately, gmm only supports a handful of devices, most of which I'm not interested in. It won't install on my lousy Samsung t629 phone (which I hate, but Opera Mini helps me tolerate). I have a really old version of gmm on my Palm TX which works great, but doesn't support GPS. I almost bought a Nokia N900 to replace my various gadgets, but then I accidentally my old car and had to buy a new one, so took myself out of the preorder queue.

Which lead to my long protracted search for some kind of mobile mapping software for our eeePC 901 running eeebuntu. GPSdrive looked promising, but I couldn't quite get it to work with my iBT bluetooth GPS, or to even scroll out of Germany for that matter. Google Earth sort of worked, but the fonts and Z-buffer were wonky, and my previous experience hooking Google Earth Plus to a GPS wasn't actually all that stellar. I even tried running the Android SDK so I could try installing GMM in the emulator, and also installed androidx86, but alas, gmm wasn't an option in their stripped-down app repositories.

Finally after many google searches, I found tangogps while simply mucking around in aptitude. I was very impressed with both the simplicity of the user interface and the power of all of the features... In addition to supporting several different map sets out of the box (including an "for testing only" google satellite maps scraper), it also has a friend-finder database similar to Google Latitude, and better yet some of the trip meter features I missed from Garmin devices. Plus the inclusion of sources such as the opencyclemap db makes it more useful to me than GMM was. It's also possible to download tiles over a region in advance for offline viewing.

I now have my eeePC linked via bluetooth to both the iBT GPS and my Samsung t629 phone to download tiles from T-mobile's network using my $10/mo. web2go plan. Unfortunately, it doesn't support search yet, but does have rudimentary routing and directions. But it does give me just what I've really wanted -- an overhead moving map display.

Someday I hope Google will make GMM available for "real" computing devices, maybe on ChromeOS or Androidx86 or better yet just as a standard java app (yes, I also looked into installing the Sun Java micro development environment and generic phone emulator, but it looked like a real mess to get things installed and then somehow connected to a real GPS). Or at least porting to the Maemo platform so it would run on the N900 and friends. But barring that, I think I can make do with tangoGPS until I maybe succumb to one of the newer Android 2 devices due out this year.

top

Palm T5 - TX touchscreen transplant

rwa2 rwa2 writes  |  more than 4 years ago

I don't know why I hadn't thought of this sooner. My Palm TX had a pretty broken touchscreen, with large unresponsive areas in the middle of the screen and in the graffiti area. I had been coping with this for years... writing really small and frustrated graffiti in the corners, and creatively using various combinations of presses around the edges to activate buttons in the middle with touchscreen averaging.

But after replacing the broken screen in my wife's eeePC a few weeks ago (it was only $50 for a beautiful new glossy screen) I thought I might try buying a replacement Palm touchscreen (which go for about $20-$30 and include the special * screwdriver). Then I remembered that I had my old broken Palm T5 lying around, which still had a nice working touchscreen. I don't know why I assumed they wouldn't be compatible earlier...

Anyway, the small bit on my leatherman fits the Palm T* screws fine, and after a bit of drunken internal surgery, the transplant was complete. My Palm TX has a new lease on life, with a nicely calibrated touchscreen and hard buttons on the front that work consistently now.

Of course, now I have to invest in some better protective gear to keep it that way... my jacket pocket just contributes too much lint.

Unfortunately, the power button still doesn't work, but there are apps to compensate for that, like PowerBtn or OffStroke.

top

Mirrored RAID read performance, where art thou?

rwa2 rwa2 writes  |  more than 4 years ago

Back before mdadm (in the days of mkraid), the Linux RAID1 driver used to give you a performance boost when reading from a mirrored array. Essentially, from 2 mirrored disks, it would read half the data from each disk and give you the whole thing almost twice as fast. At some point, they decided to change that behavior so reads would only be performed from one drive at a time. There was still some small performance boost... it would decrease average seek latency a bit by reading from the hard disk spindle that was physically closer to the sector to be read. And maybe it allowed concurrent reads, so one process could read a file from one disk while another process read a file from the secondary disk... but for some reason, that doesn't seem to increase your overall throughput by anywhere close to a factor of 2... more like 1.3 from my brief testing (and I suspect most of that gain was probably due to disk cache rather than parallel reads).

But after reading a few different Linux RAID sites today, it looks like that you can get that kind of performance boost again out of mirrored arrays by using RAID10,f2 ( --profile far=2 )! And even though it's called RAID10, it even works on arrays as small at 2 disks. It basically works by striping your data across the first half of your drives, and then striping the mirror of that data across the second half. This appears to decrease write performance by about 5% compared to RAID1 or RAID10 near=2 (the default), but the read performance finally increases again not only due to striping, but also because your disk heads now stay near the faster outer rings of your disk drives, and only has to dive down to the inner rings for mirroring writes.

So I'm pretty excited about this since I've kinda been annoyed by it for the past few year. Except that of course I now have to rebuild all my RAID1 and RAID10 arrays to use the far=2 profile :P

Here are links to some of the more useful sites with data:
http://linux-raid.osdl.org/index.php/Performance
http://blog.jamponi.net/2007/12/some-raid10-performance-numbers.html
http://home.comcast.net/~jpiszcz/raid/20080528/raid-levels.html

top

SwiftWeasel

rwa2 rwa2 writes  |  about 5 years ago

I am liking Swiftweasel, it is noticeably faster than Iceweasel / Firefox on Linux, especially on netbooks like my eeepc 901 running eeebuntu.

Unfortunately, the deb repository for it is somewhat old (v3.0.3), and current .tgz builds from sourceforge are somewhat old as well (v3.0.5 for x86, and v3.0.6 for x86-64, whereas the current iceweasel / firefox is at v3.0.7). I kinda wish SticKK of the SwiftWeasel Project would post more instructions on how to build swiftweasel from current iceweasel sources.

Until then, I've seen that "about:buildconfig" can be used to identify the compiler and options used. When I get a chance, I'd like to try grabbing the iceweasel deb-src and modifying the build options to match. Don't see anything in there about how to enable Profile Guided Optimization (PGO) which is necessary to make *nix builds of firefox javascript run as fast as Windows builds, as mentioned at this firefox benchmarking site.

Oddly enough, I ran the SunSpider javascript benchmarking suite under both Swiftweasel and Iceweasel, and Swiftweasel actually took a tad longer. I feels much snappier in day-to-day use though, probably because of some of the FasterFox extension options. The default vanilla Iceweasel on the eeepc typically pauses for a second or two on new page loads.

top

Web 2.0 Micro blogging howto

rwa2 rwa2 writes  |  more than 5 years ago Facebook seems to have suddenly hit critical mass in my friends-and-acquaintances sphere of influence. I don't really like Facebook... social engines like OKCupid and Orkut seem more fun, relevant, and informative. While Facebook seems cold and quite pointless for the most part (most of the activities involve "pokes"... exchange of vampire bites? water fights?). But it does seem to have the largest networked community going for it at the moment. It's filling the gap created by Classmates, allowing people to connect with their long-lost school peers in ways that other countries with more successful implementations of "classmates" services have enjoyed for years (such as the Russian Odnaklassniki.ru)

Anyway, I found this Mashup guide very useful in setting up Facebook and Livejournal and Twitter so they all kinda cross-post to each other. Now if only there was a way to plug my slashdot journal into the fray as well.... hmmmm

top

Eee PC 901 FTW FWIW

rwa2 rwa2 writes  |  more than 5 years ago

Picked up the black Asus Eee PC 901 20GB for my wife Sofia, to replace her 700Mhz Apple iBook. She's always been a Mac person since working for Yearbook in high school, but I finally broke her of it by buying one of her own after we got married. She's really liking the Eee PC, both for the form factor and their Linux OS. She's never been a Windows person, and on the Mac all she used was Firefox and NeoOffice to work on her MS and PhD coursework in education, so the transition to Linux has been pretty straightforward.

We still have a few quirks with their custom install of Xandros Linux to figure out, which I'll try to record here as I go along.

I'd like to replace the AsusLauncher desktop with a straight IceWM desktop + menu at some point. But since it's for my wife, I don't really want to go too overboard with customizing it.

Also need to figure out the best way to expand the root dir so we can install more software. We're getting the Grad Student edition of SPSS 16 for one of her courses this year, thankfully they sell a Linux port.

top

Keyboard

rwa2 rwa2 writes  |  more than 5 years ago

Just picked up a Casio WK-110 keyboard for my kids' piano lessons. Toy 'R' Us has them on clearance for $130, down from $200. They must be making way for the new WK-120 model. Hopefully this can tide us over for a while until we can get a nicer digital piano with pedals and hammer action, which usually run in the $500 - $800 range.

My old Yamaha PortaSound that we had been using finally broke... or at least it's at the point where it can only play drums while on battery power. I've had it with me for the better part of two decades. But the keys were small and didn't have any kind of touch response.

top

Nokia 6021 resurrected

rwa2 rwa2 writes  |  more than 7 years ago

My Nokia 6021 died the other day. Of course my wife blamed me for swapping my battery with the nearly dead one in her phone so I could use her camera to take some snaps of a family gathering.

I originally picked up an unlocked Nokia 6021 in particular because it was the only tri-band international GSM phone that supported EDGE & bluetooth, but had no built-in camera so I could take it to work. I wish the american GSM providers would figure out that there's a market for this beyond those blackberry devices. I prefer keeping my PDAs and cell phones separate so I could upgrade them independently, thank you. Plus, I typically get a better overall feature set out of $200 cell phone + a $200 PDA compared to the leading $600 "smartphone" of the time.

So the symptoms of my Nokia mobile's demise was a crash on bootup... I'd hit the power button and the screen would just flash white and then shut off again. Once in a blue moon, I could get the thing to boot up a little past the bootup screen, but it would crash again while building the menu. I could also convince the battery to charge to full, so it wasn't a low battery problem.

I pried the thing open and removed the 6 screws holding it together. Inspecting the circuitboard near the main battery contacts, I noticed a tiny little XH414X battery cell that showed signs of corrosion. Nokia had welded it to its battery contacts, so with nothing to lose (I never bother with warranties, esp. with my ~$200 price cap on most of my personal electronics), I simply twisted it out with a pair of needlenose pliers. Afterwards, the phone booted up and worked fine, and remembered all of my memory settings... everything except for the time!

So this little permanently-attached watch battery is apparently a little time bomb waiting to incapacitate your Nokia phone. I suppose mine died early due to the corrosion... I'd be the first to admit that my children and my pocket provide a pretty rough operating environment for my gear. But it's still a bit unnerving that they expect you to upgrade your phone after however many years that battery would last. But since the phone works with the internal clock battery dead, I'm not sure what to think. It's not much of an inconvenience, and my phone offers to set the time from the network on bootup anyway, so it would only be a problem if my main battery died and got replaced while I was stuck in a cave. Perhaps I just hit a weird failure mode where the corroded battery was feeding back some strange voltage that the Nokia engineers didn't expect from a normally dying watch cell.

Anyway, it has vaguely inconvenienced me for a few days while I was on international travel, but here's hoping someone will find this information useful in debugging their related Nokia phone troubles.

top

opie on an iPaq h5450

rwa2 rwa2 writes  |  more than 9 years ago I suppose I should use this space to write about technology.

I got an iPaq h5450 from work, and after toying with PocketPC 2002 for a while (didn't want to shell out the 30 bucks or whatever to upgrade to PocketPC 2003, even if it would make the built-in wifi & bluetooth work), I immediately got around to the task of installing the Linux distributions from handhelds.org on it.

It took a few weeks to play with all of the options, however, because the documentation is in shambles. I finally got the bootloader installed from an Win2k machine, and got the bootloader to install the gtk 'lite' over X 'lite' -based GPE through the RS-232 serial cradle using minicom on a Linux machine.

GPE was neat, but had a few usability issues, so I eventually backed it up (using rsync over a ppp connection) and went to the embedded Qt -based opie. I'm pretty happy with Opie. I tend to be biased towards the more idealistic gnome/gtk/gnu guys than the more pragmatic kde/qt people, but the opie app software was visibly better engineered from the user perspective.

First thing I noticed about each project was that I had to update from the unstable sources to get any decent functionality. Mostly because my hardware is relatively new, but also because the unstable apps just worked better. No big surprise there, esp. with projects under heavy development.

Though OPIE won't just run any minimally-ported X application like GPE will, the application set it does have serves my needs well, with things to handle web browsing (a stripped-down konqueror), a nice terminal with multiple session management and shortcuts to common commands, and VNC.

Just about all of the hardware works, except maybe that fingerprint reader. Most needed manual configuration, though. I have to configure the wifi card using ifconfig and wconfig on each boot and wake from sleep. Many of the FAQs are pretty dated. For the longest time I was led to believe that SD cards didn't work, but I finally stumbled across the right module to load buried in /lib/modules. But I am happy enough that the hardware support is there, even if I have to launch a script to get it to work every time. Looks like the OPIE GUI autoconfig tools are changing rapidly, though, so this will hopefully be behind us in a few months.

Still have some annoying problems. Every few weeks, it locks up hard, and I have to do several hard resets, removing the battery and everything to get it to boot. Fortunately, nothing permanent is stored in volatile memory (unlike in MS PocketPC), so this doesn't result in data loss.

I still end up primarily using my aging Visor Pro, since there's still a lot more useful/indispensible PalmOS software out there (HandyShopper, Progect, Mapopolis, etc.), but I'm hoping to get POSE working on the iPaq eventually. Also need to get multisync working enough to migrate my PIM info over. As for offline web browsing, it looks like JPluck + OPIEReader will fit the bill for what I had been using Avantgo & Plucker for. After that, I should finally be ready to ditch my Visor, but don't hold your breath :P

Slashdot Account

Need an Account?

Forgot your password?

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>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...