What is logrotate?
logrotate is a program used to rotate logs. The system usually runs logrotate
once a day, and when it runs it checks rules that can be customized on a
per-directory or per-log basis.
“Log rotation” refers to the practice of archiving an application’s
current log, starting a fresh log, and deleting older logs. Because a
“log” is a file where an application stores information that might be
useful to an administrator or developer - what it’s been doing, what errors
it’s run into, that sort of thing. So logs are good, you just usually
don’t want to keep a ton of them around. That’s where logrotate comes in.
The importance of log rotation
Logs are wonderful things when you want to track usage or troubleshoot an
application. Unfortunately the more information that gets logged, the more
disk space the log uses. Over time it can really add up.
A log left unrotated can grow to a pretty unwieldy size. Running out of disk
space because of a giant log is a problem of course, but a huge log file can
also slow down the process of resizing or backing up. Another practical
consideration is that it’s hard to look for a particular event if you have
a million log entries to skim through. So on the whole it’s a good idea to
keep log files down to a manageable size, and to prune them when they get too
old to be of much use.
Fortunately logrotate makes log rotation easy.
