From ff3a56a121bdc356847e2f25ef664ee4e37ad02c Mon Sep 17 00:00:00 2001 From: Michael Meckelein Date: Fri, 18 Jan 2008 14:22:56 +0000 Subject: *** empty log message *** --- doc/log_rotation_fix_size.html | 59 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 doc/log_rotation_fix_size.html diff --git a/doc/log_rotation_fix_size.html b/doc/log_rotation_fix_size.html new file mode 100644 index 00000000..182833b9 --- /dev/null +++ b/doc/log_rotation_fix_size.html @@ -0,0 +1,59 @@ + +Keep the log file size accurate with log rotation + + + +

Log rotation with rsyslog

Written by + Michael Meckelein

Situation

+ +

Your environment does not allow you to store tons of logs? +You have limited disc space available for logging, for example +you want to log to a 124 MB RAM usb stick? Or you do not want to +keep all the logs for months, logs from the last days is sufficient? +Think about log rotation.

+ +

Log rotation based on fixed-size file

+ +

This small but hopefully useful article will show you the way +to keep your logs at a given size. The following sample is based on +rsyslog illustrating a simple but effective log rotation with a +maximum size condition.

+ +

Use Output Channels for fixed-length syslog files

+ +

Lets assume you do not want to spend more than 100 MB hard +disc space for you logs. With rsyslog you can configure Output +Channels to achieve this. Putting the following directive

+ +

+# start log rotation via outchannel
+# outchannel definiation
+$outchannel log_rotation,/var/log/log_rotation.log, 52428800,/home/me/./log_rotation_script 
+#  activate the channel and log everything to it 
+*.* $log_rotation
+# end log rotation via outchannel
+

+ +

to ryslog.conf instruct rsyslog to log everything to the destination file +'/var/log/log_rotation.log' until the give file size of 50 MB is reached. If +the max file size is reached it will perform an action. In our case it executes +the script /home/me/log_rotation_script which contains a single command:

+ +

+mv -f /var/log/log_rotation.log /var/log/log_rotation.log.1 +

+ +

This moves the original log to a kind of backup log file. +After the action was successfully performed rsyslog creates a new /var/log/log_rotation.log +file and fill it up with new logs. So the latest logs are always in log_roatation.log.

+ +

Conclusion

+ +

With this approach you use two files for logging, each with a maximum size of 50 MB. So +we can say we have successfully configured a log rotation which satisfies our requirement. +We keep the logs at a fixed-size level of100 MB.

+ + + -- cgit