Hyper-V

If you shutdown a VM and you cannot restart it again this might be caused by Read Only Domain Controller (RODC).

If you may seen an error message that a VM cannot start with error code 0x80070569 check if the site the VM is running on has an RODC only. If this is the case you may missed to add the new VM to the "Allowed RODC Password Replication Group" of this site. The error 0x80070569 point to a Logon Failure per https://learn.microsoft.com/en-us/troubleshoot/windows-server/virtualization/starting-or-live-migrating-hyper-v-vms-fails.

Search on the Hyper-V host for System Eventlog for ID 5723 and you may see the VM machine name is not trusted by the local RODC server. Also search Hyper-V-VMMS > Admin eventlogs for event ID 15500 to find error code 0x80070569.

Now add the VM machine name into your "Allowed RODC Password Replication Group" and reboot the RODC and VM. When it comes up again the machine account will be cached locally on RODC and you can start/stop the virtual machine successfully.

Symptom:

If you run ColdFusion in virtual machines under HyperV with dynamic memory enabled you may expierence that the ColdFusion services are not started after the server has booted up. The services are set to start automatically, but are failing to start at boot time with strange and unknown error messages in system event log. If you manually start them they fire up properly.

Application log

You may run Commvault Backup Software or any other on a Hyper-V Cluster and your VSS Snapshots of the virtual machines fail from time to time.

At CommVault Virtual iDataAgent using Microsoft VSS and Hyper-V Installation, Backup and Restore problems they describe several reason for this type of failure. There recommend many missing Microsoft hotfixes (you should really install) and a disabled automount, but the top one issue - that happens most often from my expierence is - that you are just running out of disk space in one of the VMs located on the Cluster Shared Volume.

If you are running a Cacti EZ 0.6 based on CentOS 4.x inside a Hyper V Virtual Machine you will see that the machines system time runs out of sync, but you have configured NTP correctly.

Symtoms:

• If Cacti EZ runs for about one hour and you may see a time difference of ~90 seconds to your NTP time.
• "ntpdate -u ntp.example.com" command shows you differences to the current time whenever you execute it.

Solution:

• Append clock=pit as kernel boot parameter to /boot/grub/menu.lst as documented in The system time runs too fast on a Linux-based virtual machine