I have a customer with a virtual solution... a pair of session host servers, an exchange server, pair of domain controllers etc.
They reported the servers were misbehaving earlier today.
We couldn't immediately see an issue but noticed that the 'highest active time' on the session host servers is at a near-constant 100% on several of the servers. The HyperV hypervisor itself is also running at 100% highest active time.
The upshot is that users are seeing horrendous performance via RDP now.... switching between applications is taking an age and even opening MS Word is taking 30+ seconds.
The Hypervisors are Dell PowerEgde R430's connected via Iscsi (10Gb Fiber) to a Synology storage device, which provides the virtual machine storage.
I have other customers also running on the synology storage, and those customers are not experiencing an issue, so I'm confident there is no issue there; but that said I'm at a bit of a loss.
Whenever we've experienced similar issues in the past, either a backup has kicked in out of schedule and the resources are being smashed as a result, or storage maintenance tasks have kicked in. I've checked both of those things and can see no issue.
The compute resource (mem and CPU) of the hypervisors is also well within usual limits...
Does anyone have any suggestions or pointers on where to investigate next?
I can probably reboot the whole solution this evening and, given that it's a Windows environment, likely make the issue go away, but I could really do with understanding the cause.
Any help appriciated.