We've covered what vSAN is and how to set up a vSAN Cluster in a few of the earlier blog posts. Now what happens if the compute and storage capacity of your vSAN cluster is exhausted? How can the cluster capacity be increased or expanded?
Let's quickly look at fixing the mentioned problems in this blog post. You can expand an existing vSAN cluster by adding hosts or adding devices to existing hosts, without disrupting any ongoing operations.
Any of the following method can be used to expand your vSAN cluster -
1. You can simply add a new ESXi host to the cluster which is having the supported cache and capacity devices. Before adding a new host to the existing cluster verify that the drivers, firmware, and storage I/O controllers, are listed in the VMware Compatibility Guide. In order to have an even distribution of components and objects across devices in the cluster, VMware recommends creating consistently configured hosts in the vSAN cluster.
Once the new host is added to the cluster ensure that the host is seeing all it's cache and capacity devices. Post which you would need to create a disk group manually which will add capacity to the existing vSAN Datastore.
2. Second option is to move existing ESXi hosts to the vSAN Cluster by using host profile. New cluster members add storage and compute capacity. On the newly joined host, you must manually create a subset of disk groups from the local capacity devices. Again, verify that the hardware components, drivers, firmware, and storage I/O controllers that you plan on using are certified and listed in the VMware Compatibility Guide. Also, when adding capacity devices, make sure that the devices are unformatted and not partitioned, so that vSAN can recognize and claim the devices.
3. Another option is to add the capacity devices to the ESXi hosts in a vSAN Cluster if you're running low only on storage. Before doing so, ensure that the new devices are compatible as per VMware HCL. Once the new capacity drives are added you must manually add them to the disk group on the ESXi host. Once the new devices are added verify that the vSAN Disk Balance health check is green. If the Disk Balance health check issues a warning, perform a manual rebalance operation during off-business hours.
That's it for now.
I hope this was helpful to you.
Thank you for reading!
*** Explore | Share | Grow ***
Comments