l2_io_error and l2_cksum_bad are not null and growing

[Alex]

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

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

-- 
Alex