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.

RESOLVED - Newb here - ignored SMART warnings, then had 1 of two cache drives in pool fail - cannot restore cache

Featured Replies

Hello All,

I am a major newbie here...

I had ignored some SMART warnings and eventually one of my two cache drives failed.

I made a series of mistakes at this point, including a couple of reboots (without getting diagnostics first) and playing around with the size of the cache pool.

I now have replaced the bad drive with a new one. The old one was a 2 TB SSD and the secondary cache drive was a 1 TB nvme. I have replaced the bad drive with a new 1 TB SSD. Now I have:

image.png

Cache is the old Cache 2.

I have also tried to:

  • Remove all disks from the Cache Pool and restarting array with no cache drives and got an "unmatched" warning

  • Deleting the original Pool and creating a new one with two slots...still unmountable

I never actively formatted the new SSD drive.

I think the only mistake I DID NOT make was to format the nvme, so I am hoping I can still recover my Dockers. Any help for this oldie but newbie would be appreciated. I also do not have backups. So there's another mistake I will never make again...

unsoltz-diagnostics-20250530-1621.zip

Edited by JuSteve
more info

Solved by JorgeB

  • Community Expert

Was the pool btrfs or zfs? If you don't know, post the output from btrfs fi show and zpool import

  • Author

image.png

Thank you!

Edited by JuSteve
Thanks

  • Community Expert
  • Solution

With the array stopped, type: btrfs rescue zero-log /dev/nvme0n1p1

Then try again, importing the pool with just that device, and post new diags after array start, but btrfs was detecting data corruption on both pool members before, so there may be other issues.

  • Author

When you say "importing," do you mean create a new pool with just that device? Sorry, complete beginner....

  • Author

OK, I created a new pool and removed the old one, creating the new pool with one slot and using the nvme drive. It seems to have mounted and and now, for the first time, not seeing the unmountable error. It looks like it is looking for the removed drive:

image.png

The shares all seem to be back but I am getting an "unprotected" warning:

image.png

Here is the new diagnostic:

unsoltz-diagnostics-20250531-1017.zip

How would I proceed to restoring my Dockers? I'm assuming I at least need to add the second cache drive to the pool and rebalance first, correct?

Thank you for the help, @JorgeB !

Edited by JuSteve
shout out

  • Community Expert

As a first step, scrub the pool and post the results from the GUI.

  • Author

@JorgeB Results:

image.png

I also noticed that appdata and system are now located on Array?

image.png

Thank you!

Edited by JuSteve
Added tag

  • Author

I am assuming that I need to take the following steps to return this whole thing to a healthy state:

  1. Get my cache drive to a healthy state (needing and getting help on this currently)

  2. reduce the size of the cache from 2 > 1 (I'm assuming I need to do this prior to adding the new Cache drive?)

  3. add the new cache drive and increase pool size to 2

  4. rebalance the cache (does it do this automatically?)

  5. change settings for System and Appdata to Array > Cache

  6. Run Mover

  7. Change settings again on Appdata and System to be Cache only

  8. Restore my Dockers one at a time using "Reinstall with Previous Settings"

Is this about right? By the way, the VERY next step for me is to install Appdata Backup so I have a parachute next time!

Edited by JuSteve
Typo

  • Community Expert

The scrub is aborting, meaning there are other issues with the pool, I would recommend backing up and recreating it.

  • Author

What is the best backup method at this point? Unless I’m reading things wrong, the appdata is now on the array?

Edited by JuSteve
More

  • Community Expert

Just try to copy anything important you have on the pool somewhere else.

  • Author

Since it appears that the data on the Cache is only available through the pool devices and not a share, is it OK to copy the contents to an individual drive in the Array? It seems as though that's my only option...

  • Community Expert
43 minutes ago, JuSteve said:

is it OK to copy the contents to an individual drive in the Array

Yes. It is OK to do a device->device copy or a share->share copy. What you must not do is mix these in the same command as something like device->share can cause data loss.

  • Author

OK....I looked on Cache and there only seems to be directories and no files. I backed up Appdata and System which seemed to already be on the Array (so, now two copies of each). So probably OK to start over with Cache?

Edited by JuSteve
Typo

  • Author

Thanks everyone...I got my cache rebuilt and my Dockers restored. Appreciate the assistance!

  • JuSteve changed the title to RESOLVED - Newb here - ignored SMART warnings, then had 1 of two cache drives in pool fail - cannot restore cache

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

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.