Issue removing bad drive and adding replacement

[xiphosm3]

Hi all,

On one of my pools, a drive started failing with 17 bad sectors. Not a big deal typically as I will add a replacement drive to the pool, remove the bad drive, and it will rebalance and move files off of the bad drive and to the new one.

This time was different. I added the new drive to the pool, and removed the bad drive except that it didn't transfer the files off of it. The drive still has 5TB of data on it but when I attempt to add it back to the pool, i get an error stating "cannot add same disk to pool twice". The drive isn't listed under any pool drive list.

When I assign a drive letter to review the files on the drive, there are two pool.parts, both hidden and empty.

Any idea whats going on here? Do I just need to recover the data with another tool?

[Shane]

If a poolpart is empty on a removed drive that would suggest DrivePool successfully moved all the pooled files off it but failed to remove the poolpart folder itself. Did you do a normal remove, or tick any of the options? Also odd that there's two poolpart folders on it. But as the drive is still showing 5TB used... were you using it for anything besides DrivePool? Maybe check with a tool like TreeSize (run as Administrator) or similar?

[xiphosm3]

3 hours ago, Shane said:

If a poolpart is empty on a removed drive that would suggest DrivePool successfully moved all the pooled files off it but failed to remove the poolpart folder itself. Did you do a normal remove, or tick any of the options? Also odd that there's two poolpart folders on it. But as the drive is still showing 5TB used... were you using it for anything besides DrivePool? Maybe check with a tool like TreeSize (run as Administrator) or similar?

Hey Shane, thank you for the response. Nothing was used on the drive except for Drivepool. When i removed the pool, i didn't select any of the options which is why I am a bit confused.

When I try to open the poolpart folder, it states its corrupted and has 0 files and 0bytes. However I'm currently running a recovery tool on the drive which is finding the files nicely. I'm more just confused why i am having to do this very manual process on this drive.

[Shane]

That sounds like the bad sectors might've unfortunately included the file system's indexing of the drive? DrivePool normally deletes the files and folders on a drive being removed as it migrates each of them to the rest of the pool (so that the drive is all tidy for reuse); it might've run into a problem it couldn't handle there ("DrivePool: okay, that bit's copied, delete that bit" Drive's file system: "potato" DrivePool: "what?").

FWIW with a "known bad" drive I'd recommend ticking at least the first option, "Force damaged drive removal (unreadable files will be left on the disk)", maybe the second as well*, "Duplicate files later (faster drive removal)", but if the structure itself was affected that might not have helped either.

*If I know a drive has bad sectors I'd rather have it out of the pool ASAP, but mileage may vary and it doesn't do anything if duplication isn't enabled.

[Christopher (Drashna)]

Also, when removing the drive, it adds a tag to the PoolPart folder that says "this folder/drive is removed".  (the dpcmd tool also can do this, but does so without moving the data off).

And yeah, what shane said about the folder .... it sounds like the folder entry may have gotten corrupted.  This can cause issues, up to and including the "cannot be added twice" type thing. 

That said, if the data recovery software is able to get the files, those should be usable, in theory.  StableBit DrivePool stores the whole file on each disk, so provided that the recovered data isn't corrupted, they should be usable.