Emergency UNIX and Linux Support

Hi All

I have a RAID 5 array consisting of 4 drives that had a partial drive failure in one of the drives.

Rebooting shows the faulty drive as background rebuilding and mdadm /dev/ARRAYID shows three drives as in sync with the fourth drive as spare rebuilding.

However the array won't come online instead reporting itself as active, degraded, not started

I want to take the faultyesque drive out of the array as smartctl shows it as just about to fail with a reallocated sectors problem.

I've executed a stop on the array but I can't fail the faulty drive as it just reports "No such device" however mdadm -E /dev/thatdrive reports it belonging to the array and mdadm -D /dev/thatarray shows the drive in the array but with thatdrive as "spare rebuilding".

I've read assorted stuff on this for the last 7-8 hours and short of physically pulling the drive out can't see a way to get the drive out of the array, I've even done a reboot to see if that helped with no effect.

What am I missing?

Thanks in advance.

---------- Post updated at 09:13 PM ---------- Previous update was at 03:25 AM ----------

No one has any ideas?

Wow that's scary how little depth of knowledge for mdadm there is out there.

The man seems to day you can pull them all offline, but is otherwise terse, so maybe they assume if you want to limp without the bad drive, you just pull it? Maybe the facility you want is lower down, in the system device layer not the md virtual device layer.

According to what I've read elsewhere you should be able to.....

mdadm --stop /dev/thatarray

mdadm --fail /dev/thatdrive

and then the drive should no longer show as in the array.....well that's the theory but it ain't working in practice.

Try -force ?

I'd already tried with the --force option....no go I'm afraid.

I should get the replacement disks today so will be physically pulling the drive and crossing my fingers.

You did not give us very much information so it is hard to give precise answers

What flavor and version of Linux are you on?

What is the output of:

Code:

cat /proc/mdstat
mdadm --detail

Though I always found md to be stable, the Linux world seems to have fixated on the much more flexible (and thoroughly documented) Volume Management (LVM) tools. Should you recover, consider a rebuild with LVM. There are more steps and there is a learning curve involved, but these are
Outweighed by the ability to get support.