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seen Mar 19 at 13:10

Feb
23
comment Tools for Monitoring Steal Time (st)
The root cause of this one turned out to be that the ISP had the VM incorrectly configured. The guest was being told it had more cores than it actually did. This seemed to cause havoc with the scheduling. The ISP couldn't provide intelligent tech support, but we were able to "prove" the problem by disabling odd-numbered cores in /proc. Never a problem since.
Feb
4
comment Recovering data from a damaged hard-drive: the “freezer trick”
The manufacturers change chips on boards and often don't update their model numbers. Consider too shelving the drive until you find the parts or have the money to deal with it. Don't shelve it tooo long though, the parts get harder and harder to find.
Feb
3
comment Recovering data from a damaged hard-drive: the “freezer trick”
Only if you have an identical board. IMHO, if you have a second identical disk, you're probably a professional, or you care enough about the data that you should send it to one.
Oct
15
comment Walking Multidimensional arrays in Mawk
It looks like the lack of multidimensionality is going to cause such a performance and complexity issue, that I'm going to have to shift over to Perl or Python. Unfortunatley, I can't address this by installing gawk.
Oct
15
comment Walking Multidimensional arrays in Mawk
I was leaving out the question about ordering to keep this question short. You answered both questions even though I only asked one :-)
Jul
25
comment Weird behaviour case insensitivity with bash on MacOS
I haven't encountered a case insensitive shell environment before. Thanks for the help... I'm going to have to re-think some of my shell-scripts now :-(
Jun
22
comment Tools for Monitoring Steal Time (st)
I wish I could set more than one answer as the accepted answer. Both answers have been very useful :-) Thank you!
Jun
20
comment Tools for Monitoring Steal Time (st)
The spec is right, but does it matter? dual core hyperthreading v. quad-core still show up as 4 CPUs. Should Xen only allocate us 2 CPUs?
Jun
20
comment Tools for Monitoring Steal Time (st)
I added some info about the cores above in the question. These bursts of st are short-lived, but they cause a big impact to our server.
Jun
20
comment Tools for Monitoring Steal Time (st)
still waiting for their support guys to get back to us. Supposedly the "virtual dedicated" concept was to give us a real metal server. It makes scaling, backup and a few other things easier. This is not the first support ticket regarding our load problems, so if this turns out to be the cause, I'll be rather... unhappy.
Jun
19
comment Sudden burst in free memory
Oh and no hint of the OOM killer.... lots of memory free.
Jun
19
comment Sudden burst in free memory
I suspect the load afterwards is a backlog of activity. Base load on the server is a steady 2-3% with a 5% average load. I recently brought that down from higher figures by removing spamd, changing awstats jobs etc. The server is a shared web host with pop3 and imap on Dovecot. It's overtaxed, but this kind of performance probelm and this kind of weird memory behaviour is abnormal, even for a server which is under steady load.
Jun
19
comment Sudden burst in free memory
The 'bunch' is the 1.6GB. It's odd. The Swap is 2GB, but mostly unused (50MB occasionally shows up in there). vmstat -SM 3 would be hard to run in a timely fashion. When the system experiences this, sometimes the terminal is unresponsive. Applications: They freeze, we occasionally get Bug: Soft Lockup in the syslog, and their load values get artifically inflated. Everything slowly comes back.
Jun
6
comment install 2.6.32.59 on squeeze
It looks like the Debian kernel versions threw me for a loop. Like you say, it sounds like 2.6.32-42 of the Debian package contains 2.6.32.59's patches. See unix.stackexchange.com/questions/39621/… for what I'm trying to solve.
Apr
6
comment Salvage files from ext3 filesystem with physical errors
It's primarily concerned with analysing the structure of the disk and will let you do stuff like manually mount disks, specify filesystem types, manually scan for superblocks, etc. There's another sister utility called "photorec" which looks for signatures of the data. E.g., if a .doc file is on the disk, it will follow the blocks and recover the file even if there is no superblock. Photorec is probably impractical unless you can get better transfer rates or take the dd. I've used these to do data recovery, but I'm not a data recovery professional.
Mar
28
comment how to troubleshoot a network adapter on an AIX 4.3.3 machine
The card is built-in. I added the output of the commands above. I thought the card might be dead, but when I test it using the SMS utils, it comes back "ok" and even a ping through the test facilities works. i.e, under the "f4" menu of the boot. I'm almost going to give up on this one. There could be a weird hardware problem, it's an old machine. It's just surprising that I can get this far, but it just won't work.
Jan
27
comment How to remove duplicate lines inside a text file?
Just tried this on a 2G file and it took three minutes on my notebook. Not bad. I also tried uniq filename | awk '!seen[$0]++', but it wasn't any faster.