XenServer Administrator's Guide 4.1.0

XenServer Hosts

and resource pools

Procedure 2.10. To restore host sotfware and configuration

1. Run the command:

xe host-restore host=host file-name=hostbackup

2. Reboot to the host installation CD and select "Restore from backup".

2.7.5. Physical Machine failure

If the physical host machine has failed, use the appropriate procedure listed below to recover.

Warning

Any VMs which were running on a previous member (or the previous host) which has failed will still

be marked as Running in the database. This is for safety -- simultaneously starting a VM on two

different hosts would lead to severe disk corruption. If you are sure that the machines (and VMs)

are offline you can reset the VM power state to Halted:

xe vm-reset-powerstate vm=vm-uuid --force

VMs can then be restarted using XenCenter or the CLI.

Procedure 2.11. If the master has failed, but members are running

1. Run the commands:

xe pool-emergency-transition-to-master

xe pool-recover-slaves

2. If the commands succeed, restart the VMs.

Procedure 2.12. If the master and all members have failed

1. Run the command:

xe pool-restore-database file-name=backup

Warning

This command will only succeed if the target machine has an appropriate number of appropri-

ately named NICs.

2. If the target machine has a different view of the storage (e.g. a block-mirror with a different IP ad-

dress) than the original machine, modify the storage configuration using pbd-destroy and pbd-create

to recreate storage configurations. See Section 5.4.9, “PBD commands” for documentation of these

commands.

3. If you have created a new storage configuration, use pbd-plug or XenCenter's Storage ... Repair Stor-

age Repository menu item to use the new configuration.

4. Restart all VMs.

Procedure 2.13. To restore a VM when VM storage is not available

1. Run the command: