Windows Defender Exclusions

I’m just wondering if the windows client installer automatically adds itself to the Windows Defender process exclusion list?

One of my computers was “freezing” or stuttering because it was running so slow during an image backup. I checked task manager and saw that urbackupclientbackend.exe was at 100% disk utilization continuously while the backup was running. Doing a search on this forum showed a similar problem was reported when antivirus was also running on the files urbackup was opening.

So I manually added the Defender exclusions using PowerShell with the following commands:

    Set-MpPreference -ExclusionProcess "C:\Program Files\UrBackup\UrBackupClientBackend.exe"
    Add-MpPreference -ExclusionProcess "C:\Program Files\UrBackup\UrBackupClient_cmd.exe"
    Add-MpPreference -ExclusionProcess "C:\Program Files\UrBackup\UrBackupClient.exe"
    Add-MpPreference -ExclusionPath "C:\Program Files\UrBackup\"

It seems to run better now so I’m assuming the client does not add the exclusions?

I don’t think it is appropriate that applications add themselves to Defender exclusions…

I have seen a large performance difference when backing up a large number of (small) files. And yeah, it doesn’t seem to respect the (io) background priority urbackup runs as (well). It is weird that you had performance issues during a image backup, though. Maybe nowadays Defender also checks if one does raw reads from a volume…?
100% disk utilization is normal if the client disk is the bottleneck and nothing else – can especially happen with incremental image backups with not many changes and without CBT.

I can’t say for certain the 100% disk usage was the culprit of the stuttering but it was a sustained 100%. After the exclusion the disk usage seemed to dip more frequently below 100%.

I imagine it could still be something else like a network issue or hard drive issue.

I’m still watching the issue so I’ll report back if I find a different cause.