Category Archives: Sundry sysadmin
LVM with dmraid
hen adding a new disk for a customer running CentOS 4.7 on severely old hardware, I bumped into something I’ve never had happening to me before. Basically the system wouldn’t let me create the Physical Volume Continue reading
MySQL load balancing with mylbhelper
A customer of ours was in this particular situation. They had a very decent hardware load balancer for their webservers with capacity to spare. So they ended up load balancing the mysql instances through the same device and using a piece of software I’ve written called mylbhelper.
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MySQL query cache vs. memcached? Ridiculous!
Reading around on mailing lists, blog comments and forums etc. about methods of effective caching, I’ve seen people dismiss any form of caching, such as memcache, with the argument that MySQL has got a query cache anyways. This is what … Continue reading
mod_log_forensic howto
mod_log_forensic is an often forgotten yet very handy tool in debugging webservers. It gives each request a unique ID which you can then track through your log. It first writes the request prefixed with the unique ID, then it writes … Continue reading
Tail with action
Just thought I’d share a little python script I wrote the other day and have found helpful on several occasions already. It’s basically the same as `tail -f file | grep pattern`, but, if it finds a match, it allows … Continue reading