Akeeba Backup is a Joomla component which allows you to quickly and easily back up your whole Joomla installation. By default, Akeeba Backup does not have a limit on the number of backups it can store or on the amount of disk space these backups can take on your hosting account. This may become a problem if you have a large site and you create a lot of backups.
Step 1: Log into your Joomla admin area
Step 2: Go to Components > Akeeba Backup > Configuration.
Step 3: Locate the “Quota management” section.
Step 4: To enable the quota limits, check the boxes for “Enable size quota” and “Enable count quota”. Each limit has a slider through which you can set the desired threshold above which old backups will be deleted.
General recommend setting the “Size quota” to 500Mb and the “Count quota” to 7. This way when you want to create a new backup, the oldest backups will be deleted if the overall size of the backups exceeds 500Mb or if there are 7 previous backups.