cyborgworkshop.org » Random

Snowflake magnified from 93x-36000x

jason — Mon, 15 Jun 2009 21:50:03 +0000

I thought this was way cool. Looks totally fabricated.

W3 b33n 0wn3d

jason — Fri, 08 Aug 2008 14:31:10 +0000

damn. I got lazy and wouldn’t you know it, I got hacked. A guy calling himself KiLLer HaCk repainted all of my websites for me this morning around 7am. It was totally my fault, I had some boneheaded permissions on some files and he found them. He did have the kindness to spare the files and just
thrashed my index pages, so many thanks for that. I have a backup that is a couple of weeks old that I’m bringing back online and I’ll try to get most of the updates current as soon as I can.
You may notice that I’m not mad or anything like that, and for good reason. This person did very little damage (though I wish he had made backups) and he exposed a problem that could have been exploited by someone much more malicious. In the end, he did me a service and it only cost me a couple of
hours of my time. So, hang out. I’ll get everything back up and running and we’ll continue down this lovely yellow brick road shortly.

Update

I was able to talk to the guy that hit the website. Turns out it wasn’t me but someone else on my shared host that he was able to break in through. Then my shared host provider evidentlly didn’t have the tightest security in the world, so he hit everyone on the server. I feel a little better now

clock drift issues in Linux on newer motherboards

jason — Wed, 21 May 2008 14:00:50 +0000

Most newer motherboards are shipping with frequency control capabilities in the BIOS that allows the system to control the clock rate at a very granular level. Trouble is that not all motherboards do a very good job of talking to the operating system and letting them know that they are adjusting the clockrate. The end result is some major clock drift. On my Foxcon board under Ubuntu for example, I was drifting 4 seconds for every 1 minute that passed. Keeping 56 seconds per minute essentially. Come to find out, my board was set to automatically try to adjust the CPU frequency based on load in the BIOS and was doing a poor job of it. Note that this is not Linux CPU Frequency scaling that Im talking about. Im talking about the board trying to do it on it’s own. So if your new machine can’t keep time, try checking for any kind of clocking options that might be enabled in your BIOS. Saved me 100 bucks and an RMA.

Linux software RAID performance

jason — Tue, 06 May 2008 01:24:40 +0000

Just a random tidbit I thought I would post. I have a server at home acting as an iSCSI SAN. I ran a batch of hdparm tests against it, a single SATA drive in that array, a 5 disc SAS array in a compaq server and a 4 disc RAID 5 3Ware SATA array. here are the results. These are averages ran over 5 passes BTW on an otherwise silent machine. The CPU’s are all different speeds, but are all of the same class (dual core 800mhz FSB)

5 disc SAS array with 136g 10k drives

Timing cached reads: 13336 MB in 2.00 seconds = 6673.96 MB/sec
Timing buffered disk reads: 98 MB in 1.18 seconds = 83.31 MB/sec

4 disc Linux RAID 5 with 3Ware 9650SE and 500g 7200RPM drives

Timing cached reads: 6576 MB in 2.00 seconds = 3293.08 MB/sec
Timing buffered disk reads: 448 MB in 3.00 seconds = 149.20 MB/sec

Single 500g 7200 RPM SATA drive

Timing cached reads: 14220 MB in 2.00 seconds = 7119.78 MB/sec
Timing buffered disk reads: 198 MB in 3.02 seconds = 65.51 MB/sec

6 500g 7200 RPM SATA drives in a software RAID 5 array

Timing cached reads: 14364 MB in 2.00 seconds = 7191.86 MB/sec
Timing buffered disk reads: 852 MB in 3.00 seconds = 283.64 MB/sec

Now, for those of you that have storage experience, yes I didn’t mention chunk size or any of that fun stuff. But the point that I’m trying to get across is that, if you have the CPU cycles to spare, software RAID can be wicked fast.

Adoption

jason — Tue, 29 Apr 2008 14:22:11 +0000

Off topic, not technical, but we’re celebrating. We just got our login date for our adoption. We’re that much closer to growing our family. w00t!