Removing a nested pool

[Tiru]

A bit of an odd issue which will probably be easily resolved, but since I'm not sure how it happened I'm hoping to get some insight before I just start clicking buttons.

I've had a DrivePool with 10 drives as 'DrivePool E:\' for a long time and recently removed a disk due to hardware failure. It was detected by StableBit Scanner and data was moved off, worked nicely. Today I noticed I have a new pool, 'DrivePool D:\' which contains the original drivepool. In DrivePool I can move between the two pools, and on E: it notes 'This pool is part of pool DrivePool'.

Pool E: lists my 9 remaining drives; pool D: lists just the single E: DrivePool virtual drive.

When I view the individual drives there is only a single PoolPart.* folder which is what is confusing me. I was kind of expecting there would be nested folders, since it is a pool within a pool. I didn't intentionally create this so I'm wondering can I just remove the pooled E: drive from the DrivePool D:\ and return to having a single pool or is that going to confuse it and throw everything into disarray. I was browsing the forums and got the impression nested pools weren't supposed to be a thing.

Thanks in advance.

 

[Shane]

That is odd. Still, if there's no files in D:\ when you look at it in explorer then you should be able to safely Remove the E:\ "disk" from the D:\ pool and thus delete the D:\ pool without affecting the E:\ pool.

[Tiru]

Upon further investigation I think this was created, somehow, by StableBit Scanner. When it detected the damaged drive I had it attempt to recover files and the export folder for those was to be the root of E:\Public, but for some reason it may have made an entirely new drivepool. No idea how or why. It didn't put them in E:\Public but created D:\Public.

It does appear the two drives should have the same contents but they don't:

 

DrivePool(D:) only actually has 7 files totaling 231 GB, which are the 7 files that were restored during the StableBit operation. There are no hidden files, no poolPart folders on this disk. It isn't a physical disk. It is, somehow, a pool that only shows the recovered files and they already also exist on the DrivePool (E:) - I was able to find them in a poolPart folder on one of the disks that make up that pool, with a file modified time from when they were moved off the damaged disk. So, this D somehow contains essentially 7 pointers to files on other disks. There is actual content in the file, so the pool part is pointing to two places? I don't get it. I didn't think a pool worked like this, where a file can be in two different pools simultaneously, or that a pool could contain only 7 files from a disk and not the entire contents of the drive. I'm reluctant to change it since at this point I don't really have a reasonable expectation that simply removing E: from the D: pool will set it back to normal. 

I suppose, worst-case, the pool can be re-created from scratch and the data won't actually be lost. Quite odd.

 

[Tiru]

For anybody who comes across this thread in the future with a similar issue:

I wasn't able to ultimately figure out how this occurred but I decided to remove the E:\ pool from the D:\ pool using the default removal settings and that removed the extra drive letter. A SnapRAID scan of all the constituent drives that comprise my E: pool didn't find any unexpected changes, so it appears to have been a safe operation given limited testing.