
A Citrix XenServer host that is managed by Apache CloudStack will reboot itself along with all running virtual machines running on the host if there is a problem with the primary storage after a period of time. In general this is a good protection method, if the primary storage is no longer available it can cause problems for the virtual machines, Windows VMs may blue screen of death (BSOD) while Linux VMs may enter a read only file system state to protect against data loss. However you may have multiple NFS mount points to act as primary storage and may not want every VM on the XenServer host to power off with the host should this happen. It is possible to work around this by modifying the heartbeat script created by CloudStack on the XenServer host.