
VMware vSphere 5.1 Cookbook
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It is recommended to unmount a VMFS datastore before the LUN that is backing it is un-presented from an ESXi host.
It is advised that you take care of the following before you proceed with the unmount operation:
All the VMs should be migrated off to a different datastore
The datastore should be removed from a datastore cluster
The datastore should remain unmanaged by SDRS (Storage DRS)
SIOC (Storage I/O Control) should be disabled for the datastore
The datastore should not be in use as a vSphere HA Heartbeat datastore.
A VMFS volume can be unmounted from the vSphere Web Client GUI or by using esxcli at the ESXi console.
vSphere Web Client can be used to unmount a datastore. It is particularly useful when you have to unmount the datastore from multiple ESXi hosts.
The following steps will guide you through the process of unmounting a VMFS datastore using the vSphere Web Client:
Use the vSphere Web Client to connect...
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