Skip to content
View in the app

A better way to browse. Learn more.

Unraid

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

[SOLVED] HELP: Cache unmountable after removing 2nd cache pool drive

Featured Replies

I'm trying to remove 1 of 2 cache pool drives, but I'm now stuck with an unmountable cache.  What I did:

 

  1. rebalanced
  2. stopped array
  3. unallocated 2nd drive
  4. started - server froze and then read on forums need to remove drive to start
  5. removed unwanted drive and then started
  6. array starts but cache unmountable

 

Fix common problems says

 

Quote

cache (HFS250G32TND-N1A2A_FJ69N40661080954I) has file system errors (Bound to btrfs pool)

 

and suggests

 

Quote

if the disk if XFS / REISERFS, stop the array, restart the Array in Maintenance mode, and run the file system checks. If the disk is BTRFS, then just run the file system check" as the fix

 

but I can't find the option.   

 

What am I doing wrong?  Thanks 

 

PS I'm praying I can fix as I was so confident I was doing the right thing I formatted rather than removed the surplus drive as this was stated as a way to restart the array, so if I can't recover the remaining drive I might have lost some files.....

highlander-diagnostics-20170307-1702.zip

Edited by DZMM

  • Community Expert

For the future follow the FAQ instructions to remove a cache device, much safer.

 

For now your best bet is probably to try an mount it read only, copy all data and format:

 

mkdir /x
mount -o recovery,ro /dev/sdX1 /x

 

Replace X with actual device

  • Author

Thanks.  I didn't check the FAQ but I did do a few searches first and this is the one that gave me the confidence to go ahead:

 

Admittedly your next post did say read the FAQ, but I didn't get that far.

 

I tried the command but got the following error:

 

Quote

mount: wrong fs type, bad option, bad superblock on /dev/sdf, missing codepage, or helper program, or other error.

 

Should I try this?  Asking first this time

btrfs restore -v /dev/sdf1 /mnt/disk2/restore

 

 

 

  • Community Expert

You can, don't forget you need to create the destination folder before doing the restore.

  • Author

OK it seems to be qorking - lots of 'trying another mirror' entries but it seems to be working, although I got a 'we seem to be looping a lot' message on one of my PST files.  I'm assuming this is because they are large?

  • Author

Update: all files seem to be recovered.  I've put my backups in a safe place just in case.

 

Thanks for the help

  • Author

ok, I'm not quite there.  My new cache pool isn't assigned when the server boots.  I've tried running 'new config' but it doesn't work - I have to assign the drives on each boot.

 

Basically I went from 2x250GB cache pool & 1x500GB unassigned to all 3 SSDs now in the cache pool.  When I assign and then start array all is fine.

 

how do I fix please?  i've tried moving all files to the array and creating the pool from fresh.

highlander-diagnostics-20170311-0032.zip

1 hour ago, DZMM said:

ok, I'm not quite there.  My new cache pool isn't assigned when the server boots.  I've tried running 'new config' but it doesn't work - I have to assign the drives on each boot.

Boot in safe mode, assign the disks, start the array, stop the array, reboot, see what happens.

  • Author
6 hours ago, jonathanm said:

Boot in safe mode, assign the disks, start the array, stop the array, reboot, see what happens.

Thanks that worked.  I'd been booting and setting the array to not start to do the same, but i guess doing in safe mode was needed

  • 2 years later...

I'm having the same issue here.  I've started the restore on the first disk out of two.  My question is:  Do I restore the second disk to the same directory i created for the first ?  Or do I need to create a second directory for that ?

Edited by tonsofguns

  • Community Expert
21 minutes ago, tonsofguns said:

I'm having the same issue here.  I've started the restore on the first disk out of two.  My question is:  Do I restore the second disk to the same directory i created for the first ?  Or do I need to create a second directory for that ?

This thread you have posted in is nearly 3 years old, and marked solved. And you haven't given enough information for us to judge exactly what your problem is or what you may have done. The person who started the thread apparently didn't follow the correct procedure and so wound up with a problem. Is that what you did also?

 

I think there must be something about your situation that is very different than this thread. Why do you think there are 2 separate disks to be restored?

  • Community Expert

Go to Tools - Diagnostics and attach the complete diagnostics zip file to your NEXT post.

Archived

This topic is now archived and is closed to further replies.

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.