Resolving excluded objects in SharePoint backup takes multiple hours to complete

[rura_at_tivoli]

Hello

We use exclusions to exclude most of our user accounts since they don't hold valuable SharePoint data (we run OneDrive backup in a separate job).
Using exclusions allows us to add the entire tenant to the SharePoint backup thus backing up all public sites, Teams etc.
Our problem is that when the job is running it spends more than 7 hours on just resolving the excluded objects.
The result is that the total time for the job is more than 24 hours and therefore preventing us from having at least 1 daily backup.

Is this normal?

We exclude around 3000 accounts leaving roughly 350 sites to backup.
Exclusions is done with groups.
Daily data is no more than 100-400 MB.

[Polina]

Hello and welcome to the community!

Technically the background process for resolving exclusions is the same as resolving the items for backup. The more items you need to resolve - the longer processing you will experience.
Exclusions work great when, for example, you're backing up a group, but except for certain users from this group.

Considering, you have much fewer data to back up than to exclude it might make sense to reconfigure your backup job and add only the data, which you need to process. For example, you could add the required groups to the job and edit processing options for each of them - uncheck members personal items and group mail, and keep only group site for processing. Another way is to select and add only the required sites.