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May 23 2008
A while back I was asking about how to look at server load issues. I wound up using collectd, which was pretty useful. I identified a handful of disk I/O spikes - unfortunately it's hard to match these up against... read moreApril 24 2008
This week's discovery: a bug with IE7's CSS handling (I'm sure you're all very surprised), and the workaround. The bug: I have rollover submenus, set up with CSS. In Firefox and Safari they behave as expected: the submenu pops up... read moreApril 10 2008
Radio silence here of late as I have been moving old website to new website; a process which is time-consuming and gives rise to a very long to-do list, but which isn't remotely interesting to anyone else. Although I have... read moreMarch 13 2008
I have a server (LDAP and NFS) which occasionally seems to take a while to react. Load average is consistently high (10-12 for 4 CPUs, which AIUI means 2.5-3 per CPU); response may also be being affected by disk I/O.... read moreMarch 06 2008
If you're interested in SSL & Apache (a how-to). Also on the web front: the other week I was talking about CSS & child elements, and someone suggested using the :empty selector. This isn't in the CSS 2.1 spec, but... read moreMarch 03 2008
I have cron-apt set up on all my machines -- you can get it to install any updates automatically but that sounds like Bad News to me, so instead it's set to download and email me. I had a script... read moreFebruary 21 2008
I am in the process of rewriting the work website to be all CSS-shiny, standards compliant, easy to update, all that jazz. During which I have been led to really wish that CSS had a "has child" selector. It is... read moreFebruary 07 2008
Very useful article on using gnuplot to plot log data information. I used it yesterday to look at the data on LDAP response rates that I've been collecting for a few weeks, and the suggested script (with appropriate minor changes)... read moreFebruary 01 2008
Having just moved my mouse to the left of the keyboard in order to put my notebook on the right*, I am now hyper-aware of how much I use the mouse and that this is less comfortable than using the... read moreJanuary 24 2008
Occasionally it is necessary to print out a text file. There are a couple of ways of making this happen in a slightly prettier fashion than simply using lp file.txt. a2ps is one possibility - it gives you nice borders & prints by default 2 x A5 pages sideways on… read moreLDAP script to show available disks
January 10 2008
We have an NFS system which involves part of the local disks of all desktops being exported via NFS. Mostly this is consistently accessed via /disk/machinename, but some desktops have more than one local directory that’s exported. I finally got around recently to rewriting the (very old and no longer… read moreDecember 14 2007
After two replacement chassis in quick succession (timekeeping problems, followed by blown power supply), one of my machines was showing its two ethernet ports as eth4 and eth5. This probably isn’t an issue in and of itself*, but if I ever have to do stuff manually with the ethernet ports… read moreNovember 30 2007
We automatically pay for next-business-day onsite support for all our machines. I have had cause recently to access this twice, with two different companies. Company 1 (machine has what I suspect is a dodgy fan): will only send out an engineer after they have got you to run diagnostic tests… read moreNovember 22 2007
Things to look for if kerberos-enabled SSH isn’t working: Check /etc/ssh/sshd_config for lines that look like this: KerberosAuthentication yes KerberosOrLocalPasswd yes KerberosTicketCleanup yes GSSAPIAuthentication yes GSSAPICleanupCredentials yes GssapiKeyExchange yes Check that libsasl2-gssapi-mit is installed (for Debian; insert appropriate package for your system). Check that you’ve extracted the host/client.example.com key to /etc/krb5.keytab on the client you’re trying to… read moreNovember 15 2007
My webserver has been playing up of late - tending to hang. top showed some blosxom.cgi processes that had been running for some time and were using up large chunks of CPU (up to 100% occasionally). Killing these didn’t resolve the problem permanently, so I looked further. Apparently there was… read more
