Hanging or failing consolidated backups using SmartDisk. (4042556)

Date – 07/2010
Affected Product & Version – SmartDisk 1.x and up
Affected Module & Version - N/A
OS Version - All
Application Information - N/A

When doing a consolidated backup using Smart Disk, you must take into consideration the amount of space needed in the Staging pool. The Staging pool must be able to contain the original full backup job, incremental jobs associated with the full backup, and sufficient space to create a new a consolidated full backup. If the original full backup and it associated incremental backups have been de-duplicated, the data will need to be the re-hydrated in the staging pool. When planning the amount of space needed for the staging pool, also take into consideration when deduplication takes place (when, and how large a window).

Example: If the weekly full backup is one TB in size, the five day incremental backup average size is 100 GB per day. The minimum space on the SmartDisk to re-hydrate the data is 1.5 TB ((1 TB + (100 GB x5) = 1.5 TB) plus the space needed to create the new consolidated full backup (use the size of the re-hydrated data as a baseline). The space needed to do the consolidated backup is 3.0TB.

If using differential backups, the minimum space would be based upon the full backup plus the size of each differential backup for the five days, plus the space needed to create the new consolidated full backup.

Formula: Staging Pool space = (original Full backup + the total space of all incremental or differential backups associated with the full backup) x2

NOTE. The information above does not take into consideration that there may be other data in the staging pool at the same time as doing the consolidated Backup.

Please refer to the text above