Add Cache Pool from Existing BTRFS (RAID5)

[shredswithpiks]

So, long story short... I had a 3 disk BTRFS RAID5 cache pool using disks sitting in a mediasonic probox USB 3.1 enclosure. I added a 4th drive to the probox, and that caused the probox to set new serial numbers for all the disks (kind of a wtf moment).

I can still manually mount the btrfs array, but would like to put it back into a cache pool through the GUI.

If I set up a "new" cache pool and add the disks back in the same order they were (just using the "new" serial numbers), will unraid just see the btrfs filesystem and import/adopt it? Or is it going to reformat everything and try to create a brand new filesystem?

[trurl]

3 minutes ago, shredswithpiks said:

probox to set new serial numbers

Just one of many reasons USB NOT recommended for array or pools 

[shredswithpiks]

2 minutes ago, trurl said:

Just one of many reasons USB NOT recommended for array or pools 

Yup, understood. It's not critical data or anything, just a place I've been throwing old disks I've upgraded to larger disks in the main array. Kind of a nice spot for crunching large sets of data I don't need to keep around very long.

Really just looking to understand whether cache pools will try to import existing filesystems or if they create new filesystems every time - in case I can save myself a bit of time bouncing data around.

[JorgeB]

19 minutes ago, shredswithpiks said:

If I set up a "new" cache pool and add the disks back in the same order they were (just using the "new" serial numbers), will unraid just see the btrfs filesystem and import/adopt it?

This, you don't even need the same order, just start the array without any pool device assigned so the config is "forgotten", then re-assign the original members only, not the new one, start the array and Unraid will import the existing pool, then add new device.

[shredswithpiks]

12 minutes ago, JorgeB said:

This, you don't even need the same order, just start the array without any pool device assigned so the config is "forgotten", then re-assign the original members only, not the new one, start the array and Unraid will import the existing pool, then add new device.

Thanks I will give this a shot!

[shredswithpiks]

OK, that worked flawlessly! Thanks for the help!!!