1 files changed, 60 insertions, 0 deletions
diff --git a/source/tutorials/log_rotation_fix_size.rst b/source/tutorials/log_rotation_fix_size.rst
new file mode 100644
index 0000000..d2d1570
--- /dev/null
+++ b/source/tutorials/log_rotation_fix_size.rst
@@ -0,0 +1,60 @@
+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 a fixed log size
+--------------------------------------
+
+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 definition
+    $outchannel log_rotation,/var/log/log_rotation.log, 52428800,/home/me/./log_rotation_script 
+    #  activate the channel and log everything to it 
+    *.* :omfile:$log_rotation
+    # end log rotation via outchannel
+
+to rsyslog.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\_rotation.log.
+
+Conclusion
+----------
+
+With this approach two files for logging are used, 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 of 100 MB.
+