http://www.enac.northwestern.edu/~tew t e whalen -- research engineer -- psychology -- northwestern university Thu, 07 Jul 2005 15:32:04 +0000 http://backend.userland.com/rss092 en I had trouble with CGI access to Nagios after an apt-get upgrade on my debian box. I kept getting the error “It appears as though you do not have permission to view information for any of the services you requested”. The key is to remember to check that ... http://www.enac.northwestern.edu/~tew/archives/2005/01/17/fixing-nagios-on-debian/ I don’t think I’ve mentioned the path python module in detail before, so I will now. It’s amazingly useful, and so much more intuitive than the standard library equivalents (os.path, etc.). If you’re like me, and you never got the hang of iteration or recursion in bash scripting, this module ... http://www.enac.northwestern.edu/~tew/archives/2004/12/03/path-python-module/ If it’s a big pain when a workstation’s ssh keypair gets lost, back it up. #!/bin/sh HOSTNAME=`hostname` sudo cat /etc/ssh/ssh_host_dsa_key > ws_keys/ssh_host_dsa_key.${HOSTNAME} sudo cat /etc/ssh/ssh_host_dsa_key.pub > ws_keys/ssh_host_dsa_key.pub.${HOSTNAME} sudo cat /etc/ssh/ssh_host_rsa_key > ws_keys/ssh_host_rsa_key.${HOSTNAME} sudo cat /etc/ssh/ssh_host_rsa_key.pub > ws_keys/ssh_host_rsa_key.pub.${HOSTNAME} chmod go-r ws_keys/*.${HOSTNAME} http://www.enac.northwestern.edu/~tew/archives/2004/11/23/helpful-hint/ We’ve got a “data archive” here, where we store all of our raw fMRI data, for safe-keeping. Unfortunately, it’s hard to allow the kind of fine-grained access control which would allow people to insert new data but disallow alteration or removal of data. The solution I’ve come up with is ... http://www.enac.northwestern.edu/~tew/archives/2004/11/22/caretaker-indirection/ Check out that curve! Woo! I’ve got your logarithm right here! http://www.enac.northwestern.edu/~tew/archives/2004/11/15/lets-go-zipf/ I’m getting hit with Debian bug #278239. What’s happening is I upgraded the kernel on the server to 2.6.x (which gave a significant performance boost) and the standard dpt_i2o module has been subsumed by the i2o_block and associated modules. I guess the kernel headers changed too, along with the ... http://www.enac.northwestern.edu/~tew/archives/2004/11/10/i2o-adaptec-raidutils-and-26x/ So, I transplanted the brains of one of my workstations today, taking out an aging k7 and stuffing in a new Athlon 64. This required some re-jiggering of my previous availability calculations, since the bogomips are low on these new Athlons. I decided to run a quick benchmark ... http://www.enac.northwestern.edu/~tew/archives/2004/11/10/new-machine-and-x86_64-joy/ So. Dell Precision Workstation 350 has a problem when running Linux kernels in the 2.6.x series with the keyboard and busmice. If you boot them up without touching a key (say in GRUB, for instance) you’ll get a message like i8042.c: Can't read CTR while initializing i8042 in your dmesgs. This ... http://www.enac.northwestern.edu/~tew/archives/2004/11/05/curse-you-heisenbugs/ Yet another drive in yet another raid array has failed on me. This one is less important, though, so we’re not replacing it. And also, $300 for a 78 GB drive is just crazy. We’re going to let the hot spare rebuild the array, and the plan ... http://www.enac.northwestern.edu/~tew/archives/2004/08/23/going-gentle-into-that-good-night/ Yesterday, I swapped around yet another spare drive in my RAID enclosure, hoping, on the advice of the Adaptec techs, that this would stop my irritating runs-for-24-hours-and-then-dies problem. It did not. Now, I’m left with the conclusion that I’m facing a situation like that described in Adaptec knowledge base article ... http://www.enac.northwestern.edu/~tew/archives/2004/08/19/still-fighting-the-good-fight/