Having problems and your XenServer cannot connect to XenCenter? Did you have high availability enabled? If you answered yes to both these questions here is how you get your XenServer back online and functioning properly.
xe pool-ha-disableNote: If this fails try ha-disable force below
xe host-emergency-ha-disable force=true<br /> xe pool-emergency-transition-to-master --force
Note: This will force the pool and slaves to reinitialize with the pool master
xe-toolstack-restart – First command I always try before anything else
service xapi restart – This restarts a core service
xsconsole – This launches console to check pool, network config, ha, running VMS, etc.
This will get your server back up and accessible, however, this disables high availability and will need to be set back up. It’s important to note the cause of an event like this. In my case, the SR I was using to host my VMs was not sufficient and caused the outage. If this happens to you make sure you have a good SAN/NAS for hosting on a Gigabit or above connection. I’d highly recommend a 10Gbs connection or a multipath gigabit connection at the very least.