CentOS 8.x Cloudstack 4.15 HA configuration

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Home > CentOS > CentOS 8.x > Virtualization > Cloudstack 4.15 > HA configuration

To configure HA for VMs (When a host fails the VM should automatically start on another host), we need to enable option for "Offer HA" for the compute offering with which the VM is created. If you go to Infrastructure -> Service offerings -> Compute offerings, you can check whether "Offer HA" is true for the offering or not.

Similarly if you click on any instance name under Instances, in details tab you can see value for "HA enabled" to understand whether this VM is HA enabled or not.


For above HA please note:

  • When an HA-enabled VM crashes, CloudStack detects the crash and restarts the VM automatically within the same Availability Zone. HA is never performed across different Availability Zones. CloudStack has a conservative policy towards restarting VMs and ensures that there will never be two instances of the same VM running at the same time. The Management Server attempts to start the VM on another Host in the same cluster.
  • There is also option to enable / disable HA at host level. We have not tested that yet. Most probably if that is enabled, then all machines on that particular host will have HA enabled.
  • During testing we observed that VMs started on other hosts 5 minutes after failure. Hence there might be some 300 second / 5 minute timer to detect failure.



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