HP SmartArray P400: How to repair failed logical drive?

Solution 1:

The answer is not pleasant. There's a high probability that your array is in a "waiting for rebuild" state, where there's another failing disk in the RAID5 array set that's preventing the recovery from completing. This is why you should avoid RAID5 these days. It doesn't help that these are SATA drives... The likelihood of problems is even higher. Try powering the system off (letting the drives spin down) and powering back on. Follow the prompts at the BIOS array screen and choose the F2 option to "reenable all logical drives". This may kickstart the rebuild process.

Otherwise, it's a rebuild/recovery with new disks.