OMS logical drive performance counters do not have the current instancename drive

Question

We use Azure OMS to monitor many of our on-premises servers.

When using the LogicalDisk (*) \% Free Space performance counter, there are some non-existent instance names, for example HarddiskVolume170, HarddiskVolume89, ...

When checking perfmon on the server, I see 3 copies of the logical drive for the free space performance counter.

• C:
• HarddiskVolume1
• _Total

When checking OMS logs, there are clearly some other instances. If you check the account, they have been active for a limited period of time.

What are these names of other instances? Do these temporary logical disks appear? I would like to clarify these examples.

thanks in advance!

Answer 1

It seems that some tools / software creates temporary virtual disks like Azure Backup Agent. These information disks are added to the performance counter logs and transferred to the analytics log.

We really didn’t have such a decision. But in our warning, it is clear that its temporary / virtual instance can be ignored.