Cache Unmountable: No file system

[GyroDragona]

Earlier today I was noting that Plez was not loading poster images. I went and checked UnRAID just to find the message "Unmountable: No file system" to the right of the cache. I have no clue what happened. Nothing about the setup has been changed in a good while and I have no clue what to do to fix it.

 

 

unraid-syslog-20200528-2325.zip

unraid-diagnostics-20200528-1627.zip

Edited May 28, 2020 by GyroDragona

[JorgeB]

One of the devices is considered missing (despite being assigned), this suggests the superblock is damaged, and it's failing to mount read/write with a single device due to no redundancy, at least partially (this could be the result of the pool not being redundant if it was created during v6.7.x due to a bug):

 

May 28 12:33:14 unRAID kernel: BTRFS warning (device sdc1): chunk 101054414848 missing 1 devices, max tolerance is 0 for writeable mount
May 28 12:33:14 unRAID kernel: BTRFS warning (device sdc1): writeable mount is not allowed due to too many missing devices

 

You should be able to recover the data by mounting read only, see here.

 

[GyroDragona]

43 minutes ago, johnnie.black said:

One of the devices is considered missing (despite being assigned), this suggests the superblock is damaged, and it's failing to mount read/write with a single device due to no redundancy, at least partially (this could be the result of the pool not being redundant if it was created during v6.7.x due to a bug):

 

May 28 12:33:14 unRAID kernel: BTRFS warning (device sdc1): chunk 101054414848 missing 1 devices, max tolerance is 0 for writeable mount
May 28 12:33:14 unRAID kernel: BTRFS warning (device sdc1): writeable mount is not allowed due to too many missing devices

 

You should be able to recover the data by mounting read only, see here.

 

Is there a way to do this with mounting the main array while mounting the cache array as read only and just shifting it all over to the protected array? I'm not super good with messing about with commands on UnRAID.

 

Do you have any guesses about what might cause corruption to the superblock? The server has a UPS that's only half a year old and can keep the server running for about an hour with drive activity and I have not done any hard power downs or resets of the system in a non clean manner. It started giving problems while it was all still running.

[JorgeB]

32 minutes ago, GyroDragona said:

Is there a way to do this with mounting the main array while mounting the cache array as read only and just shifting it all over to the protected array?

Yes, just start the array as is, cache will still be unmountable and you can try the recovery options.

 

32 minutes ago, GyroDragona said:

Do you have any guesses about what might cause corruption to the superblock?

Not without the diagnostics from when the problem started, also see here for better pool monitoring.

[GyroDragona]

19 hours ago, johnnie.black said:

Yes, just start the array as is, cache will still be unmountable and you can try the recovery options.

 

Not without the diagnostics from when the problem started, also see here for better pool monitoring.

 

It kicked out:
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.

[JorgeB]

Make sure you try all the options (except check --repair) on the FAQ on both cache devices, if none of them work best bet is to ask for help on #btrfs on freenode IRC. It's usually frequented by actual btrfs developers or very experienced users and they are very helpful there.

[GyroDragona]

14 hours ago, johnnie.black said:

Make sure you try all the options (except check --repair) on the FAQ on both cache devices, if none of them work best bet is to ask for help on #btrfs on freenode IRC. It's usually frequented by actual btrfs developers or very experienced users and they are very helpful there.

I have followed those instructions on the link but it just kicks out the same bad superblock there and I can't seem to talk in that IRC group and there does not seem to be and instructions on how to gain that right within the group. I'm kind of out of options and my server has been doing for about 4 days now.

 

With it being a two drive cache is it possible to bring up both drives with info from the second drive?

Edited May 30, 2020 by GyroDragona

[JorgeB]

9 hours ago, GyroDragona said:

With it being a two drive cache is it possible to bring up both drives with info from the second drive?

Like mentioned you should try the command on both devices (and both should always be connected), please post a screenshot of terminal (including the commands) after typing these commands, I find it odd that none of them worked:

mkdir /x
mount -o degraded,usebackuproot,ro /dev/sdc1 /x

Assuming device letters are the same as the screenshot if not make the appropriate correction.

 

[GyroDragona]

12 hours ago, johnnie.black said:

Like mentioned you should try the command on both devices (and both should always be connected), please post a screenshot of terminal (including the commands) after typing these commands, I find it odd that none of them worked:

mkdir /x
mount -o degraded,usebackuproot,ro /dev/sdc1 /x

Assuming device letters are the same as the screenshot if not make the appropriate correction.

 

 

Oh, it didn't kick out an error. Is there a way to know if data from both drives or just the one is there?

 

Where do I copy stuff so it is on the protected array to make it work from the protected array for now?

Edited May 31, 2020 by GyroDragona

[JorgeB]

13 hours ago, GyroDragona said:

Is there a way to know if data from both drives or just the one is there?

Post output of:

btrfs fi usage -T /x

 

13 hours ago, GyroDragona said:

Where do I copy stuff so it is on the protected array to make it work from the protected array for now?

Create a new share called e.g. backup and then copy from /x to /mnt/user/backup

[JorgeB]

On 5/30/2020 at 10:03 PM, GyroDragona said:

I can't seem to talk in that IRC group and there does not seem to be and instructions on how to gain that right within the group.

You just need to register your nick.

[GyroDragona]

19 hours ago, johnnie.black said:

Post output of:

btrfs fi usage -T /x

 

 

19 hours ago, johnnie.black said:

Create a new share called e.g. backup and then copy from /x to /mnt/user/backup

Is there anything special I need to do maintain permissions and ownership with the copy?

Edited June 2, 2020 by GyroDragona

[JorgeB]

Just do a regular copy, you can use for example midnight commander (mc on the console), not sure all data will be available since it was a raid0 pool, copy what you can.

[GyroDragona]

Multicore on #btrfs spent hours trying to help me but there just wasn't any luck to be had. There was just too much weirdness going on with the drive and btrfs. Superbocks were in the wrong places, the drive vanishing from the btrfs setup. Something with unraid mangled things and I have no clue how it managed to do it.

 

I gave up.

 

I ended up wiping the drives, formated them and got them properly set up as a mirror btrfs. I wasn't able to recover any useable/useful data from the old setup other than a single config file. It's a wash. That said, thank you very much for your help and time in trying to help me out.

Edited June 3, 2020 by GyroDragona

[JorgeB]

That's a shame, and thanks for the update, also never forget for the future that you should have backups of anything important.

[GyroDragona]

I have had CA Backup / Restore Appdata installed for ages but I guess it didn’t take or something. I thought it was doing backups but I guess I didn’t save the configuration or something got messed up with it. I don’t know. I do keep backups but this time they just were not being made. 

Edited June 7, 2020 by GyroDragona