This have happened more than 2 case now
Hardware PE R420 with single CPU, enough RAM, RAID 1 with hotspare, Perc 310, Windows 2012 R2 with Hyper V enabled. about 2 - 3 Virtual Machines, VSS disk queue is disabled in the network adpater. Windows and Firmware is up to date.
User environment: about 10 users.
This was the configuration picked as the environment does not need anything intensive.
issue: Randomly, the system will behave very sluggishly anything disk related, opening up task manager, opening up a folder, virtual machine behaviors.
i will restart the physical server, with a clean reboot and no virtual machines running, anything disk related, opening up a zip file, pull up services.msc, will be very slow, takes about 10 - 15 seconds to pop up.
idrac shows everything is clean, vd and raid is healthy.
this only goes away when you power the server off and cold power start it. since restart does not help, it is leading to think it is a firmware / hardware issue.
edit: CPU <3%, ram only used about 500MB, disk activity <1MB /sec, basically everything in resource monitor is flat.
any suggestions will be appreciated.