At 08/17/2016 12:05 AM, Rakesh Sankeshi wrote:
2) after EDQUOT, can't write anymore.
I can delete the data, but still can't write further
So it's a underflow now.
3) tested it without compression and also with LZO and ZLIB.. all
behave same way with qgroup. no consistency on when it hits the quota
limit and don't understand on how it's calculating the numbers.
Even without compression?!
That's a really big problem then.
Workload please, it's an urgent bug now.
It's better to provide the scripts to reproduce it.
And for the meaning of the numbers, for rfer(reference) it means the
size of all extents the subvolume has referred to, including both data
and metadata.
For excl(exclusive), it means the size of all extents that only belongs
to the subvolume.
And since it's all about size of extents(on-disk), for compression case,
it's the size after compression.
Also, if one subvolume only referred to part of an extent, the whole
extent size will be accounted.
Last but not least.
Considering there is quite a lot of report about hitting ENOSPC while
there is still a lot of unallocated space,
is it reporting error message like "No space left on device" (ENOSPC) or
"Quota exceeded"(EDQUOT)?
Thanks,
Qu
In case of ext4 and xfs, I can see visually that it's hitting the quota limit.
On Mon, Aug 15, 2016 at 6:01 PM, Qu Wenruo <quwen...@cn.fujitsu.com> wrote:
At 08/16/2016 03:11 AM, Rakesh Sankeshi wrote:
yes, subvol level.
qgroupid rfer excl max_rfer max_excl parent child
-------- ---- ---- -------- -------- ------ -----
0/5 16.00KiB 16.00KiB none none --- ---
0/258 119.48GiB 119.48GiB 200.00GiB none --- ---
0/259 92.57GiB 92.57GiB 200.00GiB none --- ---
although I have 200GB limit on 2 subvols, running into issue at about
120 and 92GB itself
1) About workload
Would you mind to mention the work pattern of your write?
Just dd data with LZO compression?
For compression part, it's a little complicated, as the reserved data size
and on disk extent size are different.
It's possible that at some code we leaked some reserved data space.
2) Behavior after EDQUOT
And, after EDQUOT happens, can you write data into the subvolume?
If you can still write a lot of data (at least several giga), it seems to be
something related with temporary reserved space.
If not, and even can't remove any file due to EQUOTA, then it's almost sure
we have underflowed the reserved data.
In that case, unmount and mount again will be the only workaround.
(In fact, not workaround at all)
3) Behavior without compression
If it's OK for you, would you mind to test it without compression?
Currently we mostly use the assumption that on-disk extent size are the same
with in-memory extent size (non-compression).
So qgroup + compression is not the main concern before and is buggy.
If without compression, qgroup works sanely, at least we can be sure that
the cause is qgroup + compression.
Thanks,
Qu
On Sun, Aug 14, 2016 at 7:11 PM, Qu Wenruo <quwen...@cn.fujitsu.com>
wrote:
At 08/12/2016 01:32 AM, Rakesh Sankeshi wrote:
I set 200GB limit to one user and 100GB to another user.
as soon as I reached 139GB and 53GB each, hitting the quota errors.
anyway to workaround quota functionality on btrfs LZO compressed
filesystem?
Please paste "btrfs qgroup show -prce <mnt>" output if you are using
btrfs
qgroup/quota function.
And, AFAIK btrfs qgroup is applied to subvolume, not user.
So did you mean limit it to one subvolume belongs to one user?
Thanks,
Qu
4.7.0-040700-generic #201608021801 SMP
btrfs-progs v4.7
Label: none uuid: 66a78faf-2052-4864-8a52-c5aec7a56ab8
Total devices 2 FS bytes used 150.62GiB
devid 1 size 1.00TiB used 78.01GiB path /dev/xvdc
devid 2 size 1.00TiB used 78.01GiB path /dev/xvde
Data, RAID0: total=150.00GiB, used=149.12GiB
System, RAID1: total=8.00MiB, used=16.00KiB
Metadata, RAID1: total=3.00GiB, used=1.49GiB
GlobalReserve, single: total=512.00MiB, used=0.00B
Filesystem Size Used Avail Use% Mounted on
/dev/xvdc 2.0T 153G 1.9T 8% /test_lzo
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