Guys, i 'found' a spare WD 6TB drive which had been previously used in an Unraid setup.

 

I decided to add it to my existing server ... the drive showed up ok as an UD and offerred up a 'clear' function which i chose to go with.

 

Once cleared i chose to add it to my setup as Disk4, next in line and all appeared well being offerred up a 'Format' optio for the disk, i again chose to go with.

 

Thereafter the drive showed up as Disk4 'unmountable with no file system'.

 

There being something wrong i chose wrongly or rightly to remove the disk and am currently preclearing with just the 1 cycle.

 

Problem i can foresee is that once precleared will i be able to just add the disk back?

 

Currently the disk is being emulated as Disk4 but with an unmountable file system.

 

Do i need to do anything BEFORE i reintroduce the disk back to the array, there's my question, a bit long-winded i agree ...

 

Any suggestions/advice welcomed, thanks!!

 

35 minutes ago, superloopy1 said:

next in line and all appeared well being offerred up a 'Format' optio for the disk, i again chose to go with.

 

Thereafter the drive showed up as Disk4 'unmountable with no file system'.

Disk should have been formatted by Unraid, if it wasn't you should post diags, unassigning it and precelaring won't solve anything.

 

Try formatting the emulated disk, than add the disk back to rebuild, if format still doesn't work post diags.

Thanks Johnnie, that worked a treat and i now have an xfs formatteed emulated Disk4 so should be able to add back once preclear finishes (may as well let it run). Strange how formatting the 'cleared' (not precleared nb) disk just wouldnt format when introduced to the array, i did clock an error something along the lines of missing an unmountable mask?? Just left the disk as showing an 'auto' filesystem. Ring any bells?

Edited July 4, 20197 yr by superloopy1

1 minute ago, superloopy1 said:

Ring any bells?

No, would need the diags.

Not going to happen now, sorry shouldve posted earlier. Let you know if the add back throws up any probs. Cheers!

Found this

 

'

Jul  3 19:19:16 smtower root: mount: /mnt/disk4: wrong fs type, bad option, bad superblock on /dev/md4, missing codepage or helper program, or other error'

That just means there isn't a valid filesystem, can't see why the format failed.

ok, thanks for your efforts, i'll see wha happens after the preclear. All LOOKS well atm.

Similar thing;

I've added a disk to my unraid server, it appeared as an unassigned drive, I stopped the array and replaced Parity 2 disk with this one. No question to have it formatted or cleared, it just was added when I assigned it as Parity disk 2 and started the array back up.

 

The reason I didn't do a preclear is because this disk came from a HP server, which already had the disk tagged as 100% OK for XFS. Also, since my unraid uses xfs too, it only needs to 'quick format', because there's journalling and a TOC, XFS doesn't care if there are 0s or 1s on the surface, unraid doesn't care if it was a zero or a one and will just use its own roadmap for the new parity disk anyway. I don't really see an advantage in zeroing an entire 6TB 'to prevent errors' and add another bunch of useless write/read cycles to shorten the disk's lifetime. This, preclearing, in my opinion, is being highly overrated over in these forums. This is XFS we're talking about, and these are fairly new drives, with fairly new controllers and new hardware accessing them. Nobody at Western Digital/HGST, Seagate or Samsung will ever tell you to 'preclear' a disk for use in an XFS array.

10 minutes ago, fluisterben said:

I stopped the array and replaced Parity 2 disk with this one. No question to have it formatted or cleared, it just was added when I assigned it as Parity disk 2 and started the array back up.

That's normal, since parity doens't have filesystem, there's nothing to format, it also doens't need clearing since it's not a data disk, just a parity sync will start as soon as the array is started.

8 hours ago, johnnie.black said:

That's normal, since parity doens't have filesystem, there's nothing to format, it also doens't need clearing since it's not a data disk, just a parity sync will start as soon as the array is started.

Could you explain to me why one would want to 'preclear' other disks, since it is being written to and accessed by the exact same controls that the parity disk has on it. It's not like its controller does something different in either case, it asks for data and knows where it is on the storage medium, just like with any disk in the array.

Just now, fluisterben said:

Could you explain to me why one would want to 'preclear' other disks,

Currently the only advantage of preclearing disks it to test them, not needed for Unraid for some time now since data disks are cleared in the background with the array available, and parity disks never needed to be cleared, only data disks.

Just to say that this all went ok and the disk was added to the emulated (and formatted to xfs) disk4. So, all i lost was a lot of time as the disk rebuilt. Still doesnt answer the question of why the 'cleared' disk failed to format automatically when added into the array the first time around. Guessing i'll never know eh.