help on forever incremental

  • 11 September 2023
  • 1 reply


good morning,

 i resell our commvault backup shared infra as a multitenant backup service to final customers (basic backup of windows/linux clients and servers, just fileservers no db or other).

they choose between different retention policies, but all are quite the same, an incremental backup at day with retention of (15/30/60/120/365) AND a synthetic full each weekend (just in case the incremental chain got “corrupt”….).

actually our customers pay for the TOTAL logical used space for their own backup.

the problem is that longer retention periods costs much more in space AND price (a synthetic full each week for 1 year it’s a lot).

they demand to have just something like a forever incremental, with 1 full at the begin on the chain of backup and conseguent incrementals, and every day the 1day full will “shift” do right to become the new full...(something like that so the no longer pay also for each week synt full).


how can i lower the fulls/synthetic fulls to lower logical disk space usage WHILE not risking long incremental chains on long retention periods? for example an incremental only for 1 year is fine (customer will pay for first day full and 364 incremental, BUT i am scared that without in-middle syntechic full if something goes wrong...i am in serius trouble…

how can i match optimal logcal space accounting WITH forverer incremental backup trust?

thank you 

1 reply

Badge +2

Hi @mgambetti , 

Thanks for raising this up. 

The Synthetic full is the consolidation of the previous Full+Incremental backups. This does not add up any/much extra data, since synthetic full backups do not back up data from the client computer. 

Please refer more details on this from the below article:
Synthetic Full Backups

Also, (1 Full+ 364 Incremental ) backups will have almost same size of data written on the disk as 1 SF backup consolidating all these backups.