In the pooled machine environments (non-persistant machines) or customizable (pooled with personal Vdisk), the Citrix broker removes the machine differential disk and replaces it with a new one on every machine start. In some environments with XD 5.6 and 7.5/7.6 this deletion is not correctly made and the differential disks are built up in the VM directories, becoming disk space consuming.
The service activation can be performed from the Flexxible|SUITE r console, using the option Configuration → Parameters. The fields to fill are:
DeletedDifferencingCopy: True or False to activate or deactivate this functionality.
DeletedDifferencingDeleteDays: The number of days that the differential disk will be stored in the temporary folder.
DeletedDifferencingDiskPath: UNC path to the temporary folder, where the differential disks are stored. This field is mandatory, even though those removed disk copies aren't kept.
DeletedDifferencingHostingUnit: Hosting unit list, separated by semicolon, which we want to remove the differential disks from (in order to know where to search for that hosting units, plese see the following image).
DeletedDifferencingTimeRange: hour range that this job will be run. E.g. "23-6" would be from 11 pm until 6 am.
NOTE: In VDIOS 3 we may find it in CLEANUP SYSTEM / SETTINGS.
We may find the hosting unit name in the following screen in Flexxible|SUITE:
About storage preservation, please, see also "Automatic deletion of un-used catalog base disk images"