we have "Failed Logical Drive - Drive Failure" and "Status: Failed - Incomplete array" our issue happened after a weekend powerdown and restart. The Array has other logical drives on the same physical disks and they are optimal and can be accessed ok. We do not have any backend failures, all physical hdd's are green are visible in Storage manager.
i have reseated all components and done various restarts (exp520's on first leave a while then power-on ds5020). Infact we have 3 arrays which have 1 logical drive failure on each, each of these logical drives contain VMFS and all other logical drives in these arrays are ok.
I have rebooted (ds5020 controller off 1st and exp520 trays 2nd (trays in no order which is correct!))
read link status shows no errors all looks normal.