On 6/7/20 10:34 AM, Michał Mirosław wrote:
On Sun, Jun 07, 2020 at 03:35:36PM +0800, Qu Wenruo wrote:
On 2020/6/7 下午1:12, Michał Mirosław wrote:
Dear btrfs developers,
I just added a new disk to already almost full filesystem and tried to
enable raid1 for metadata (transcript below).
May I ask for your per-disk usage?
There is a known bug (but rare to hit) that completely unbalance disk
usage can lead to unexpected ENOSPC (-28) error at certain critical code
and cause the transaction abort you're hitting.
If you have added a new disk to an almost full one, then I guess that
would be the case...
# btrfs filesystem usage .
Overall:
Device size: 1.82TiB
Device allocated: 932.51GiB
Device unallocated: 930.49GiB
Device missing: 0.00B
Used: 927.28GiB
Free (estimated): 933.86GiB (min: 468.62GiB)
Data ratio: 1.00
Metadata ratio: 2.00
Global reserve: 512.00MiB (used: 0.00B)
Data,single: Size:928.47GiB, Used:925.10GiB
/dev/mapper/btrfs1 927.47GiB
/dev/mapper/btrfs2 1.00GiB
Metadata,RAID1: Size:12.00MiB, Used:1.64MiB
/dev/mapper/btrfs1 12.00MiB
/dev/mapper/btrfs2 12.00MiB
Metadata,DUP: Size:2.00GiB, Used:1.09GiB
/dev/mapper/btrfs1 4.00GiB
System,DUP: Size:8.00MiB, Used:144.00KiB
/dev/mapper/btrfs1 16.00MiB
Unallocated:
/dev/mapper/btrfs1 1.02MiB
/dev/mapper/btrfs2 930.49GiB
The old disk is full. And the fact that Metadata has a raid1 profile prevent further metadata allocation/reshape.
The filesystem goes RO after the mount ? If no a simple balance of metadata should be enough; pay attention to select
"single" profile for metadata for this first attempt.
# btrfs balance start -mconvert=single <mnt-point>
This should free about 4G from the old disk. Then, balance the data
# btrfs balance start -d <mnt-point>
Then rebalance the metadata as raid1, because now you should have enough space.
# btrfs balance start -mconvert=raid1 <mnt-point>
The operation failed and
left the filesystem in readonly state. Is this expected?
Definitely not.
If your disk layout fits my assumption, then the following patchset is
worth trying:
https://patchwork.kernel.org/project/linux-btrfs/list/?series=297005
I'll give it a try.
Best Regards,
Michał Mirosław
--
gpg @keyserver.linux.it: Goffredo Baroncelli <kreijackATinwind.it>
Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5
