l2_io_error and l2_cksum_bad are not null and growing

[Alex]

Hello.

As I see this patch seems to be pretty old. How can it be that it 
haven't been included in the stable branche since then? The problem is 
that I can't afford making experiments on the production server. Is 
there any official solution of the issue?

Alex

10/20/14 10:26 PM, Andriy Gapon пишет:
> On 20/10/2014 20:32, Alex wrote:
>> Hello.
>>
>> We seem to have a problem with l2arc on zfs system on 10.1-BETA1 FreeBSD
>> 10.1-BETA1 #1 r271710 server. The server has a l2arc cache configured from Intel
>> SSD 480G disk. The problem is that l2_io_error and l2_cksum_bad values are
>> constantly growing, however there are no traces of any hardware malfunctioning.
>> As for now, the values are
>> kstat.zfs.misc.arcstats.l2_io_error: 1501
>> kstat.zfs.misc.arcstats.l2_cksum_bad: 19480
> Please see if the following patch might help
> https://github.com/avg-I/freebsd/compare/review/l2arc-write-target-size.diff
>
>> Here is the output of zpool status:
>>    pool: zpool
>>   state: ONLINE
>>    scan: none requested
>> config:
>>
>>      NAME                               STATE     READ WRITE CKSUM
>>      zpool                              ONLINE       0     0     0
>>        mirror-0                         ONLINE       0     0     0
>>          diskid/DISK-WD-WMC1P0DFSF47p2  ONLINE       0     0     0
>>          diskid/DISK-WD-WMC1P0DEFERYp2  ONLINE       0     0     0
>>      logs
>>        gpt/zil0                         ONLINE       0     0     0
>>      cache
>>        gpt/cache0                       ONLINE       0     0     0
>>
>> errors: No known data errors
>>
>> Here is the output of zfs-stats -L:
>> ------------------------------------------------------------------------
>> ZFS Subsystem Report                Mon Oct 20 19:29:38 2014
>> ------------------------------------------------------------------------
>>
>> L2 ARC Summary: (DEGRADED)
>>      Passed Headroom:            72.42m
>>      Tried Lock Failures:            360.55m
>>      IO In Progress:                65
>>      Low Memory Aborts:            101
>>      Free on Write:                7.09k
>>      Writes While Full:            16.90k
>>      R/W Clashes:                11
>>      Bad Checksums:                19.48k
>>      IO Errors:                1.50k
>>      SPA Mismatch:                1.18m
>>
>> L2 ARC Size: (Adaptive)                555.88    GiB
>>      Header Size:            0.21%    1.17    GiB
>>
>> L2 ARC Evicts:
>>      Lock Retries:                10
>>      Upon Reading:                0
>>
>> L2 ARC Breakdown:                272.76m
>>      Hit Ratio:            0.35%    949.30k
>>      Miss Ratio:            99.65%    271.81m
>>      Feeds:                    2.19m
>>
>> L2 ARC Buffer:
>>      Bytes Scanned:                20.45    PiB
>>      Buffer Iterations:            2.19m
>>      List Iterations:            139.97m
>>      NULL List Iterations:            5.58k
>>
>> L2 ARC Writes:
>>      Writes Sent:            100.00%    567.37k
>>
>> Any help is welcome. Best regards
>>
>