How to migrate iSCSI datastores to NFS datastores in a VMware ESX host

This article describes how to migrate iSCSI datastores to NFS datastores from a VMware ESX host. You might want to complete this procedure for the following reasons:

iSCSI is not the right choice for your datastores based on the performance or stability of the Isilon iSCSI implementation. If you deploy a large number of virtual machines (VMs) from a large number of iSCSI LUNs, then there will be a resource exhaustion, when the resources necessary to perform an action are entirely consumed and LUNs might become read-only when there are multiple concurrent sessions, when multiple iSCSI clients are accessing the same VM simultaneously.

You want to migrate the VMs temporarily to a datastore (from iSCSI) for maintenance reasons and you have an NFS datastore readily available.

Procedure

NOTE
This procedure contains general steps for migrating iSCSI datastores to NFS datastores in VMware ESX. For specific instructions for each step, see the product documentation for VMware ESX.
The migration process from iSCSI datastore to NFS datastore can take a long time.

1. On the ESX host, identify which iSCSI datastores need to be converted to NFS datastores.
2. Identify any VMs and templates that exist on the iSCSI datastore, then:
   1. Convert templates to VMs.
   2. Migrate all VMs to an existing NFS datastore where they can be converted back to templates.
3. Remove the iSCSI datastores from the ESX host.
4. Remove dynamic and static discovery of targets from the ESX host's storage adapter.
5. In the ESX NFS datastore, convert any VMs which need to be converted back to templates.