Note: Virtual machines 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/ESXi hosts.
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 LUNs to the ESX/ESXi hosts, in accordance to your SAN's documentation and best-practices.
Rescan the HBA of the ESX/ESXi hosts.
Confirm that the virtual machines return to a normal state, as opposed to Inaccessible.
Power on the virtual machines.
Alternate method
Shut down the virtual machines.
Shut down the ESX/ESXi hosts for the duration of the downtime.
Start the ESX/ESXi hosts and confirm that the LUNs are discovered and accessible.