In the previous blog post, we discussed about configuring a vSAN Cluster.
After you enable vSAN on a cluster, a single vSAN datastore is created. It appears as another type of datastore in the list of datastores that might be available, including Virtual Volume, VMFS, and NFS.
vSAN combines the persistent disks in your hosts over a vSAN network to create a single shared datastore. Hence, if you put one of the hosts in the cluster in maintenance mode, that host won't contribute any of its capacity to the vSAN Datastore, and you'll notice that the vSAN Datastore's overall capacity has decreased.
A single vSAN datastore can provide different service levels for each virtual machine or each virtual disk. In vCenter Server, storage characteristics of the vSAN datastore appear as a set of capabilities. You can reference these capabilities when defining a storage policy for virtual machines. When you later deploy virtual machines, vSAN uses this policy to place virtual machines in the optimal manner based on the requirements of each virtual machine.
A vSAN datastore has specific characteristics to consider -
1. vSAN provides a single vSAN datastore accessible to all hosts in the cluster, whether or not they contribute storage to the cluster. Each host can also mount any other datastores, including Virtual Volumes, VMFS, or NFS.
2. You can use Storage vMotion to move virtual machines between vSAN datastores, NFS datastores, and VMFS datastores.
3. Only magnetic disks and flash devices used for capacity can contribute to the datastore capacity. The devices used for flash cache are not counted as part of the datastore.
To an administrator, it appears and functions just like any other datastore with one significant exception that the vSAN datastore is object-based. A vSAN datastore contains the following object types:
1. VM Home Namespace
The virtual machine home directory where all virtual machine configuration files are stored, such as .vmx, log files, vmdks, and snapshot delta description files.
2. VMDK
A virtual machine disk or .vmdk file that stores the contents of the virtual machine's hard disk drive.
3. VM Swap Object
Created when a virtual machine is powered on.
4. Snapshot Delta VMDKs
Created when virtual machine snapshots are taken. Such delta disks are not created for vSAN Express Storage Architecture.
5. Memory object
Created when the snapshot memory option is selected when creating or suspending a virtual machine.
I'll end this post here in order to keep it concise.
Thank you for reading!
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