How to set up log cleaning in Magento

In order to make sure that your Magento is not being slowed down by a huge amount of old log records, it is recommended that you set up its log cleaning function to automatically purge old logs.
You can do this from the Magento admin area

System > Configuration > Advanced  > System > Log Cleaning.

Once there, modify the value for Save Log, Days. The default value is 180 but we recommend changing it to 60 or even 30 days.
Then set Enable Log Cleaning to Yes and click Save Config to save the changes.
Note that the Log Cleaning functionality depends on the Magento cron. You need to make sure you have set up the cron in order for your log cleaning to work properly.