Storage devices might need to be placed into maintenance mode to conduct planned downtime operations. When this is the case, a couple of options are available to place a datastore into this state.
If you datastore is in SDRS cluster than you can put you datastore into the maintenance mode. Then all the VM’s reside insight that datastore is automatically migrated into the other datastore in the SDRS Cluster.
For sake of this example, I am going to put my “ISCSI1_DataStore” into maintenance mode. You can see it is in SDRS cluster.
In Step one, verify how many VMs are in this datastore.
From WebClient-> select your datastore-> Related Objects-> Virtual Machines.
Now put this datastore into the maintenance mode.
Right Click into the DataStore->All vCenter Actions ->Enter Maintenance Mode.
If SRDS did not find any Perquisite issue then it will show you the below recommendation screen. Means what it is going to do. Verify it and Click “Apply Recommendations”
As you can see below in recent task. It will show you both VMs are now migrated to the other datastore in the SDRS Cluster. When all VMs will be migrated then it will automatically put the datastore for maintenance.
If you can see below. “ISCSI1_Datastore” storage icon has been change. Its mean storage is in maintenance mode now.
When you done with the datastore maintenance. You can exit it from the maintenance.
Another option to place a datastore into maintenance mode is to unmount the datastore. When you unmount a datastore that is shared to multiple ESXi hosts, you will be prompted with a list of the shared hosts. The datastore will be unmounted from all selected hosts and will no longer be visible to those hosts. The datastore will remain mounted to the other hosts, allowing them to continue to access the data on the datastore
Before unmout your selected datastore make sure following prerequisite should meet as highlighted in the below screen shot.
To unmount a datastore right click on the Datastore -> All vCenter options-> Unmount Datastore.
Read the Information carefully and select from which host you want to unmount -> Click “OK”.
Verify you Datastore are “inactive” state now
When you done with the datastore maintenance. Then you can mount it back by right click on the datastore -> all vCenter Actions-> Mount Datastore.
Select in which host you want to mount.
Your datastore is now back and ready for operations.