Rebuild Cache pool

[wambo]

Hey there,

after I noticed some problems with syncthing, it turned out the SSD of my (bigger) cache pool has given out (lots of read errors, couldnt be mounted, filesystem not recognized in unraid...) - I managed to copy the partition on my Desktop, the drive didn't seem faulty there actually but I'm gonna replace the drive with 2 drives now, so I have parity... 

Until those drives arrive, I was thinking of using an nVME in an USB enclosure as replacement - I mirrored the faulty disk onto that, but it turns out I can't just add this device to the pool and keep using it.

So I can still mount the "stand-in" drive and copy over the files manually.

 

But this is where I'm not sure: where should I copy the files to, so Unraid won't be confused?
Onto the Pool (as if the mover has already moved them?) onto the new SSD (once they're here)?
Or is Unraid agnostic to "on which disk" files are lying, as long as they're still in the proper share?
 

Edited November 1, 2023 by wambo

[JorgeB]

23 minutes ago, wambo said:

but it turns out I can't just add this device to the pool and keep using it.

Which filesystem is the current pool using?

[wambo]

1 minute ago, JorgeB said:

Which filesystem is the current pool using?

btrfs

[JorgeB]

You can add a device to create a mirror, see here:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=480417

 

[wambo]

Yes, that part seems easy.
My real problem is how to get the "old"/"rescued" data back into the system - since the original drive won't be recognized anymore - even though I can mount it with a USB-Sata adapter. (that makes me wonder whether one of my cables internally are broken - can't test that before I get a new SATA drive though)

Should I copy the files onto the new drives once installed, or can I just move them onto the HDDs?
Or is there a way to make the system "take" the "stand-in" nvme disk and just "continue" buiseness (and then I add a Sata for redundancy and replace the nvme in a 3rd step) ?

[JorgeB]

You can just copy the data back.

 

[wambo]

Onto the array? Or only onto the new pool disk, once I have it?

[trurl]

5 minutes ago, wambo said:

onto the new pool disk

 

[wambo]

OK. For some reason I thought I could access the cache pool's disks just like I can access the arrays disk - which wouldve made it complicated.

I'm still not sure what the original problem is... the SSD is fine outside, and probably would be fine inside if I formatted it again, but unraid couldn't mount/recognize its old filesystem (the original pool)

[JorgeB]

15 hours ago, wambo said:

the SSD is fine outside, and probably would be fine inside if I formatted it again, but unraid couldn't mount/recognize its old filesystem (the original pool)

You can post the diags after array start to see the error.

[wambo]

Yes, I'm free of errors now, with the old SSD formatted newly as 2nd device in the old pool (main device new SSD). 
While I was at it, I removed a smaller SSD along with a 2nd pool and moved all this to the big pool with parity (probably also not the best idea looking back, shouldve checked it more, ran all backups again before I changed another thing)


I found the errors in syslog before, but I just convinced myself too early that it's the drive failing not the filesystem having an error (possibly only in unraid). Memo: bring the whole problem to support.

But thx for the quick answers. I consider this solved.