Re: Critical error from Tree-checker

[Archange <archange@archlinux.org>]

Le 13/09/2024 à 09:29, Qu Wenruo a écrit :
> 在 2024/9/13 14:55, Archange 写道:
> [...]
>>> And it's indeed a false alert.
>>>
>>> In that case, as long as you still have unallocated space, you can
>>> just relocate the system chunks:
>>>
>>> # btrfs balacne start -s <mnt>
>>>
>>> Which should move the system chunks to new locations and will not
>>> utilize the first 1MiB reserved space.
>>
>> # btrfs balance start -s /
>> ERROR: Refusing to explicitly operate on system chunks.
>> Pass --force if you really want to do that.
>>
>> According to https://btrfs.readthedocs.io/en/latest/btrfs-balance.html,
>> -s requires -f, so I guess I should continue with that?
>
> Yes.

Hum, no success:

# btrfs balance start -s --force /
ERROR: error during balancing '/': No space left on device
There may be more info in syslog - try dmesg | tail

# dmesg
[ 2919.917607] BTRFS info (device dm-0): balance: start -f -s
[ 2919.918105] BTRFS info (device dm-0): 1 enospc errors during balance
[ 2919.918108] BTRFS info (device dm-0): balance: ended with status: -28

Indeed,

# btrfs filesystem show /dev/mapper/root
Label: 'root'  uuid: e6614f01-6f56-4776-8b0a-c260089c35e7
     Total devices 1 FS bytes used 439.69GiB
     devid    1 size 476.87GiB used 476.87GiB path /dev/mapper/root

There is unused space though, but not sure how to reclaim it.

$ btrfs filesystem df /
Data, single: total=472.87GiB, used=438.21GiB
System, single: total=4.00MiB, used=80.00KiB
Metadata, single: total=4.00GiB, used=1.48GiB
GlobalReserve, single: total=512.00MiB, used=0.00B

As advised on the balance page, I’ve tried to run with `usage=0` as 
filter (for both m, s and d), but the result is always:

Done, had to relocate 0 out of 480 chunks

> And I also recommend to convert your metadata and system chunks to DUP,
> if there are enough unallocated space.
> (If have more devices then RAID1).
>
> It looks like the old mkfs defaults to SINGLE for SSDs, but nowadays we
> keep DUP no matter if it's SSD or not.

Alright, but I guess I need to solve -ENOSPC first…

Thanks,
Archange