SQL Server backup to DataDomain slow

[Rohail2004]

We’re backing over 150 VM’s via Veeam 5.0.2 version, our backbone is 10GB and we’re backing to DataDomain. For past months they have been backing up properly, finishing it on time and backup speed was from 120-180MB/s, but for past weeks two of my big SQL servers which has over 1.2TB data is taking forever to back up, before it was taking couple of hours, and now it is taking over 18hours to complete. I have not made any changes at the Veeam nor at the VMware level. I’m wondering if someone has experienced the same issue where it used to backup faster, but overtime it got slower.. any ideas/suggestions would be highly appreciated. Thanks.

[Gostev]

Sounds like these SQL started to generate a lot of changed blocks.