Unable to Connect to High Availability Enabled XenSever Pool and All Servers in Pool are in Emergency Mode
Article ID: CTX131127
Updated On:
Description
This article provides resolution to connectivity issues to the pool in XenCenter. Following are some of the issues that you might experience:
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Cannot connect to the pool in XenCenter
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Cannot start or migrate the virtual machines, although the virtual machines are active and running.
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All the servers are in an emergency mode
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If you run the command cat /etc/xensource/pool.conf, the former pool master server points to one of the slave servers, and all the slave servers point to the pool master server.
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The pool master server indicating it is a slave of itself.
Resolution
To resolve the preceding issue, complete the following procedure:
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Connect to the pool by using a utility such as PuTTY.
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Run the following command on all the servers in the pool:
# xe host-emergency-ha-disable -
Run the following command:
#xe-toolstack-restart -
If the servers in the pool do not restart, run the following command on any one of the servers, which you want to assign as the pool master:
#xe pool-emergency-transition-to-master -
Run the following command:
#xe pool-recover-slaves -
If the servers in the pool do not restart, run the following command:
pool-emergency-reset-master master-address=<IP address of the new master from the previous command> -
On the master server, run the following command:
#xe pool-recover-slaves
The servers in the pool start. -
Re-enable High Availability by using XenCenter.
Problem Cause
When High Availability is disabled and the pool master and one or more of the slave servers in the pool self-fence or lose power at the same time, the other servers nominate a new master.
After the old master server and the hosts start up again, the servers do not contain the updated details of the changed pool master server. These servers enter into an emergency mode and elect each other as the master server.
If the master server fails when it starts again, it cannot communicate to any other machines in the pool, it displays itself as a slave and points to itself.
Issue/Introduction
