When physically moving an array with running virtual machines, follow this best practice procedure:
- Shut down all virtual machines utilizing the targeted SAN storage, or migrate the virtual machines to standby/alternate storage.
- Unpresent the targeted SAN's Logical Units (LUs) from the ESX hosts, according to the applicable steps below:
VMware ESX 3.x
- Unmask the SAN LUs from your VMware ESX Servers (remove visibility or access). For additional steps and information, refer to your SAN vendor documentation.
- Select an ESX Server in your host inventory, its Configuration tab, then Storage Adapters.
- Rescan the ESX Server's Host Bus Adapters (HBAs).
- Verify that the LUs no longer appear in the lower pane when selecting each of your HBAs.
VMware ESX 4.x
For instructions on how to safely unpresent LUs from a ESX 4.x host, see Removing a LUN containing a datastore from VMware ESXi/ESX 4.x (1029786).
After completing these steps, verify that the array's LUs are no longer visible to the VMware ESX 4.x hosts, and no dead paths persist.
Note: Virtual machines will display as Inaccessible if their datastores are not accessible or mounted. Through the detailed procedure in this article, this behavior is expected. They will return to a normal state after the original storage devices are re-presented to the VMware ESX servers.
- Complete your scheduled downtime on the SAN. Proceed to the remaining steps only after the SAN components are confirmed available or online.
- Re-present the LUs to the ESX hosts, in accordance to your SAN's documentation and best-practices.
- Rescan the VMware ESX Servers.
- Confirm that the virtual machines return to a normal state, as opposed to Inaccessible.
- Power on the virtual machines.
- Shut down the virtual machines.
- Shut down the VMware ESX hosts for the duration of the downtime.
- Start the VMware ESX hosts and confirm that the LUs are discovered and accessible.
- Start the virtual machines.
Based on VMware KB 100277