Commvault Data Sanitization/Erasure Support

Pruning

During normal operations Commvault software prunes (erases) aged (no longer being retained) data in order to free up media storage space. To accomplish this, Commvault software prunes data on disks and tapes using the underlying media’s standard deletion process.

• For disk media, this means the underlying file index entry is removed resulting in the associated file fragments being released for reuse.  The data is then logically removed from Commvault software. The data on media is untouched until overwritten by data.
• For tape media, the tape is logically marked in Commvault software as Spare media and is made available for reuse. However, the data is still logically available in Commvault software as “aged” data and can be used for restore operations until the data has been overwritten.

Delete Backup Data and Delete Archive Data

Backed up or archived data may be deleted so that it is no longer available for browsing and recovery. The Delete Data by Browsing operation makes all versions of the data on backup media inaccessible for browsing and recovery, but the actual data remains on the media until it is no longer retained and subsequently erased by Commvault software. This applies to both disk and tape media.

Erase Spare Media

Erase Spare Media operation ensures that data on tape media cannot be recovered once all data on the media is no longer retained.  A Full Erase Spare Media operation is done by writing an EOD (End of Data) maker at the beginning of the tape (in the first byte) with a repeating DSS (Data Set Separator) pattern written to the end of the tape to overwrite the existing data.

WARNING: There are numerous data recovery tools available that can be used to read deleted data on disk or tape media that has not been overwritten. Some sophisticated data recovery tools can even recover data that has been overwritten. It is because of this that Commvault recommends using encryption when backing up or archiving sensitive data.

Sanitization

The CVDiskEraser tool is a disk sanitizing tool used to sanitize pruned data space on storage disks/mount paths according to industry standards. The following industry sanitization standards are supported.

• USD - (Default) United States Defense Department Standard 5220.22-M
• BSI - German BSI Verschlusssachen-IT-Richtlinie
• SCH - Bruce Schneier’s Algorithm
• GUT - Peter Gutmann's Algorithm
• DSX - Royal Canadian Mounted Police DSX Method.

Note: BSI standard is considered to be the most secure method of erasing the data.

Before using the tool you must ensure that as per the data aging regulations set in your organization, all aged data on the disk/mount path has been pruned. A Physical Pruning Status Check workflow is provided so you can verify whether the data of specified clients was physically pruned during the data aging process.

Note: There are numerous third-party sanitization and secure erase tools available that can be used to permanently erase individual files, or entire hard disks or tapes. We highly recommend contacting your Commvault software support organization before using any of these tools.