My cache is no longer mountable

[HomerJ]

Hi all

 

I'm in version 6.12.0-rc6 and plugins etc are updated. I've just noticed that my 3 cache drives which are formatted btrfs are unmountable and unRAID is telling me to format, but I have stuff on them. 

 

Is this because with all the recent updates I need to select something so the btrfs drives are recognised?

 

I don't really know what to do next coz all was working fine a couple days ago and it's only changed due to the updates. Any help will be much appreciated. 

[HomerJ]

Diagnostic file is attached. tower-diagnostics-20230525-0932.zip

[JorgeB]

Try this, if the log tree is the only problem it may help:

 

btrfs rescue zero-log /dev/nvme1n1p1

 

[HomerJ]

17 hours ago, JorgeB said:

Try this, if the log tree is the only problem it may help:

 

btrfs rescue zero-log /dev/nvme1n1p1

 

This fixed it! Thanks for your help!

 

If you get a spare moment, would you be able to explain how you found the problem? 

 

Should I change the btrfs file system to something else?

[JorgeB]

The log shows that the log tree failed be read.

 

6 hours ago, HomerJ said:

Should I change the btrfs file system to something else?

Usually something else causes this issue, not directly btrfs related, but you can try a different fs if you prefer, also note that this issue tends to re-occur, if it does would recommend re-formatting the fs.

 

[HomerJ]

16 hours ago, JorgeB said:

The log shows that the log tree failed be read.

 

Usually something else causes this issue, not directly btrfs related, but you can try a different fs if you prefer, also note that this issue tends to re-occur, if it does would recommend re-formatting the fs.

 

Thank you so much for your help!

 

If I change file systems, which do you think I should choose? NB it's cache. 

[JorgeB]

I assume current pool is raid1 with the 3 devices?

[HomerJ]

On 5/27/2023 at 6:02 PM, JorgeB said:

I assume current pool is raid1 with the 3 devices?

Yes

[JorgeB]

For multi device pools you can use btrfs or zfs, so you could change to zfs, but note that there's no 3 device raid1 option with zfs, you can have 2 or 4 devices in raid1, with 3 devices you can only make a 3-way mirror.

[HomerJ]

On 5/25/2023 at 6:02 PM, JorgeB said:

Try this, if the log tree is the only problem it may help:

 

btrfs rescue zero-log /dev/nvme1n1p1

 

G'day again!

 

I've had this issue occur a few times since it first happened, and this solution has fixed it each time. But what would actually cause this to happen?

[JorgeB]

If it keeps happening I would recommend to backup and reformat the pool.