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).

QUESTION:

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