unusual data growth of domain controllers

[mcz]

Hi everyone,

I'm having a backup job since ages which would also process two domain controllers (windows server 2019). Those backups are written to a SOBR and as a result to a capacity tier.
The used space on the capacity tier normally stays quite consistent, some few TBs increase/decrease are normal for that environment. However, there have been huge increases within the last few months and I first suspected other vm's just to realize that those two domain controllers would cause the increase.

For example, according to the veeam one "billing report" the small fileserver consumes constantly 3 TB over the last 4 weeks while the two DCs (both have around 70 GB diskspace) had an increase of 1 TB!! What are they doing? One DC has an increase of 700 GBs and I took a look at the installed applications: Almost nothing. vmware tools, antivirus, veeam guest agent and such tools that would never write tons of data to the disk - and even if, then at least not persistent data. No SQL server...

Just to be clear: There has absolutely been zero changes regarding retention, immutability period, etc. Just the uprgrade to the current product release (12.2).

If just don't get it why those vms would consume many additional TBs over the course of some months when they were consistent in the past as well. Now the questions is, if that is due to the backup target datastore (did something change in v12.2) or is it due to the OS? I find it hard to judge that as even support has had a tough time in the past to answer me some of similar questions...

Very happy for every possible input. Thank you!

Edit: 700 GB in 30 days means more than 23 GB of changed data per day - that's quite a lot when there are only 6 GB disk space left and it's a third of the whole disk!

[tyler.jurgens]

Any other change going on with those two servers? Increased Antivirus activity? Logging? Have you checked into the server itself to see if there is a lot of write activity happening to explain the increased usage?