With automatic backups enabled, csstored automatically manages the number of backup copies retained in your backup database files using a circular backup system.
csstored stores backups in your backup database directory until either the maximum number of backup copies have accumulated, or the maximum disk space allowed has been reached. At that point, it purges backup copies (oldest first) until it reaches the minimum number of copies to retain and it is under the disk space threshold.
There are a cluster of ics.conf parameters that control circular backups. These parameters have default values, and do not require further customization. If you wish to tune how backups work in your system, see Tuning Automatic Backups.