Hello Gianluca,

I have ISCSI SAN here and not FC but process should be very similar.

Correct operation is

Storage maintenance -> detach -> remove

 

Once you have removed the storage, Ovirt will release the sanlock.

Note that your server will still “see” the device and multipath will still list it as active.

 

You can now unmap LUN using your SAN manager.

If your multipath is correctly configured, device will “fail” but nothing else (multipath and server won’t hang).

You will be able to perform basic list operations via server shell without experiencing freeze or locks.*

Ovirt will continue to scan new devices so you won’t be able to manually remove them until you unmap devices from SAN manager.

 

If you need to remove devices manually, it is advised to follow this guide.

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/removing_devices.html

 

* If you do face command freeze etc, re-enable LUN mappings and check your multipath.conf