ARC consume more than 3 times of physical memory (Was: ZFS L2ARC checksum errors after compression).

[Lev Serebryakov]

On 07.01.2017 15:29, Lev Serebryakov wrote:

>>>> because of the confusing variable names I made a mistake in the patch that I
>>>> offered you.  Could you please try a new slight different patch?
>>>> Also, I think that there could be another problem in addition to the one that I
>>>> see.  But I am quite busy at the moment, no time to investigate.  Maybe on the
>>>> weekend or some time next week.
>>>
>>>  Nope. Second version of patch doesn't help either. Still unrealistic
>>> high compression ratio (ALLOC/SIZE, slightly less than 2 on mostly
>>> uncompresseable data), 16.0E of FREE since ALLOC becomes greater than
>>> SIZE and lot of checksum errors since the same moment.
> 
>> I see.
>> Could you please send me full output of the following commands?
>> zpool status -v
>> zpool list -v
>> zdb -CC $pool
>  Any news on this issue? Should I file formal PR?
  I've got this:

output from zfs-stats:

ARC Size:                               274.09% 39.83   GiB
        Target Size: (Adaptive)         100.00% 14.53   GiB
        Min Size (Hard Limit):          12.50%  1.82    GiB
        Max Size (High Water):          8:1     14.53   GiB


"screenshot" of top:

Mem: 103M Active, 875M Inact, 13G Wired, 12M Cache, 1448M Free
ARC: 40G Total, 141M MFU, 10G MRU, 1568K Anon, 65M Header, 249M Other
Swap: 8192M Total, 8192M Free

 This box has only 16G of physical memory.

-- 
// Lev Serebryakov

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