No-op power profile changes during windows agent backup?

[hpadm]

Whenever a windows agent-based backup job starts or finishes on our physical server hosts, the system event log records the following:

Event 12, UserModePowerService:
Process C:\Program Files\Veeam\Endpoint Backup\Veeam.EndPoint.Manager.exe (process ID:6472) reset policy scheme from {381b4222-f694-41f0-9685-ff5bb260df2e} to {381b4222-f694-41f0-9685-ff5bb260df2e}

This is the UUID for the 'Balanced' power scheme. I used 'powercfg /query' before and after and saw no changes. So it seems as if it's doing some kind of system-wide change to a power setting that's already set. Whatever it is, I suggest using some kind of temporary API if possible, instead of altering the system settings.

I checked the documentation, and for workstations the only related note I found was about enabling 'wake up timers' on workstations. The documentation for servers does not include this note. And our servers all have it enabled, which is the default setting.

(Originally submitted as free support case #05458116 but it timed out.)

[Dima P.]

Hello hpadm,

Server edition should not interfere with the power plans (indeed this is a functionality for free/workstation edition). I've asked support team to reopen the case and start the investigation. Thank you for your post!

[hpadm]

It seemed unusual, because even if it was related to wake timers, that's something you configure one time during agent installation, not just before and just after a backup job. The phrasing of the event message suggests that it actually tried switching power profiles, or something. The most logical reasoning is that it's trying to prevent the host from going to sleep in the middle of a backup job (but there are more appropriate APIs for that). Another weird thing is that it's resetting the power profile ... to itself, doing nothing.

Hm.

Code: Select all

Endpoint\...\Job.Backup.log
[06.06.2022 00:00:03] <01> Info     [SleepLocker] Enable sleep prevention
[06.06.2022 00:00:03] <01> Info     [SleepLocker] Sleep prevention power scheme params AC: True 4294967295, DC: True 300
...
[06.06.2022 00:38:38] <01> Info     [SleepLocker] Disable sleep prevention

There is a set of WinAPI calls - PowerCreateRequest, PowerSetRequest, PowerClearRequest - that are able to prevent sleep, however the documentation mentions some caveats, like a time limit when on battery power, or the ability of the user to force sleep mode. Maybe there is a more fitting API intended for backup jobs.

[Dima P.]

Thank you. Support team will reach you to collect all the logs from Veeam Agent side of things. Stay tuned!