Symptom
On Windows servers with deduplication enabled, at regular intervals the backup size is increased.
Below are several screenshots showing the problem:
Reason
The problem is not with Veeam software, but with deduplication on Windows Server.
When configuring deduplication, a memory cleanup job is configured to optimize deduplication, by default this is done every Saturday at 02:35.
There is type of cleaning Garbage Collection
- Regular.
- Complete performed every 4 cycles.
It is this complete cleaning (Full Garbage) that is problematic because it analyzes and optimize all the blocks on the disk.
Solution
The solution to the problem is disabled Full Garbage using the registry.
On servers where deduplication is enabled, enter the following command:
reg add HKLM\System\CurrentControlSet\Services\ddpsvc\Settings /v DeepGCInterval /t REG_DWORD /d 0xffffffffLinks :