How-to Manage Virtual Machine HA Group tagging
Table of Contents
Introduction
Virtual Machine "High Availability Groups" or "HA Groups" is a metadata tagging feature in the ITS Private Cloud to tag virtual machines as a group or redundant pairs. The criteria to have a valid HA Group is:
Domain separation
Group relationship
If any of the above criteria is not met, meaning that VMs are not properly separated or related, notifications will be sent to virtual machine administrators.
Domain Separation
The ITS Private Cloud provides four (4) public domain (FD), which consist of one or more ESXI hosts and Datastore Clusters grouped together according to their physical location in the datacenter. Domain separation indicates that a group of VMs, say App-Node[1-4]
, must be running in different domains:
App-Node1 -> FD1
App-Node2 -> FD2
App-Node3 -> FD3
App-Node4 -> FD4
Group Relationship
All virtual machines must be tagged properly.
vss-cli --columns name,moref,domain.name,'group[*]' compute vm get {vmId} ha-group
Create HA Group
Get list of virtual machines to create group, for this example:
App-Node[1-4]
Run the following command:
vss-cli compute vm set App-Node1 ha-group -r App-Node2 App-Node3 App-Node4
For further options to create an HA group run
--help
.From the moment the HA Group is created, our automated check will verify its validity every 3 hours (domain separation and relationship).
To verify the ha-group run the following command:
vss-cli compute vm get App-Node1 ha-group
Note that if membership exceeds the number of public FDs (4), no alerts will be triggered as long as 4 nodes are compliant.
Remove member from HA Group
Removing a virtual machine from an HA group is simply done by running the following command:
To verify the ha-group run the following command:
Virtual machine decommissioning updates any related HA Group automatically.
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