[OpenIndiana-discuss] Slow zfs writes

Ram Chander ramquick at gmail.com
Tue Feb 12 05:07:10 UTC 2013


So it looks like re-distribution issue. Initially  there were two Vdev with
24 disks ( disk 0-23 ) for close to year. After which  which we added 24
more disks and created additional vdevs. The initial vdevs are filled up
and so write speed declined. Now  how to find files that are present in a
Vdev or a disk. That way I can remove and re-copy back to distribute data.
Any other way to solve this ?

Total capacity of pool - 98Tb
Used - 44Tb
Free - 54 Tb

root at host:# zpool iostat -v
                capacity     operations    bandwidth
pool         alloc   free   read  write   read  write
-----------  -----  -----  -----  -----  -----  -----
test       54.0T  62.7T     52  1.12K  2.16M  5.78M
  raidz1     11.2T  2.41T     13     30   176K   146K
    c2t0d0       -      -      5     18  42.1K  39.0K
    c2t1d0       -      -      5     18  42.2K  39.0K
    c2t2d0       -      -      5     18  42.5K  39.0K
    c2t3d0       -      -      5     18  42.9K  39.0K
    c2t4d0       -      -      5     18  42.6K  39.0K
  raidz1     13.3T   308G     13    100   213K   521K
    c2t5d0       -      -      5     94  50.8K   135K
    c2t6d0       -      -      5     94  51.0K   135K
    c2t7d0       -      -      5     94  50.8K   135K
    c2t8d0       -      -      5     94  51.1K   135K
    c2t9d0       -      -      5     94  51.1K   135K
  raidz1     13.4T  19.1T      9    455   743K  2.31M
    c2t12d0      -      -      3    137  69.6K   235K
    c2t13d0      -      -      3    129  69.4K   227K
    c2t14d0      -      -      3    139  69.6K   235K
    c2t15d0      -      -      3    131  69.6K   227K
    c2t16d0      -      -      3    141  69.6K   235K
    c2t17d0      -      -      3    132  69.5K   227K
    c2t18d0      -      -      3    142  69.6K   235K
    c2t19d0      -      -      3    133  69.6K   227K
    c2t20d0      -      -      3    143  69.6K   235K
    c2t21d0      -      -      3    133  69.5K   227K
    c2t22d0      -      -      3    143  69.6K   235K
    c2t23d0      -      -      3    133  69.5K   227K
  raidz1     2.44T  16.6T      5    103   327K   485K
    c2t24d0      -      -      2     48  50.8K  87.4K
    c2t25d0      -      -      2     49  50.7K  87.4K
    c2t26d0      -      -      2     49  50.8K  87.3K
    c2t27d0      -      -      2     49  50.8K  87.3K
    c2t28d0      -      -      2     49  50.8K  87.3K
    c2t29d0      -      -      2     49  50.8K  87.3K
    c2t30d0      -      -      2     49  50.8K  87.3K
  raidz1     8.18T  10.8T      5    295   374K  1.54M
    c2t31d0      -      -      2    131  58.2K   279K
    c2t32d0      -      -      2    131  58.1K   279K
    c2t33d0      -      -      2    131  58.2K   279K
    c2t34d0      -      -      2    132  58.2K   279K
    c2t35d0      -      -      2    132  58.1K   279K
    c2t36d0      -      -      2    133  58.3K   279K
    c2t37d0      -      -      2    133  58.2K   279K
  raidz1     5.42T  13.6T      5    163   383K   823K
    c2t38d0      -      -      2     61  59.4K   146K
    c2t39d0      -      -      2     61  59.3K   146K
    c2t40d0      -      -      2     61  59.4K   146K
    c2t41d0      -      -      2     61  59.4K   146K
    c2t42d0      -      -      2     61  59.3K   146K
    c2t43d0      -      -      2     62  59.2K   146K
    c2t44d0      -      -      2     62  59.3K   146K



On Tue, Feb 12, 2013 at 6:39 AM, Jason Matthews <jason at broken.net> wrote:

>
>
> I am going to offer to obvious advice...
>
> How full is your pool?  Zpool performance degrades as the pool fills up and
> the tools don't tell you how close you are to the cliff -- you find the
> cliff on your own by falling off of it. As a rule of thumb, I keep
> production system less than 70% utilized.
>
> Here is a real life example. On a 14.5TB (configured) pool, I found the
> cliff with 250+GB still reported as free. The system continued to write to
> the pool but throughput dismal.
>
> Is your pool full?
>
> j.
>
> -----Original Message-----
> From: Ram Chander [mailto:ramquick at gmail.com]
> Sent: Monday, February 11, 2013 4:48 AM
> To: Discussion list for OpenIndiana
> Subject: [OpenIndiana-discuss] Slow zfs writes
>
> Hi,
>
> My OI box is expreiencing slow zfs writes ( around 30 times slower ).
> iostat reports below error though pool is healthy. This is happening in
> past 4 days though no change was done to system. Is the hard disks faulty ?
> Please help.
>
>
> # zpool status -v
> root at host:~# zpool status -v
>   pool: test
>  state: ONLINE
> status: The pool is formatted using a legacy on-disk format.  The pool can
>         still be used, but some features are unavailable.
> action: Upgrade the pool using 'zpool upgrade'.  Once this is done, the
>         pool will no longer be accessible on software that does not support
> feature flags.
> config:
>
>         NAME         STATE     READ WRITE CKSUM
>         test       ONLINE       0     0     0
>           raidz1-0   ONLINE       0     0     0
>             c2t0d0   ONLINE       0     0     0
>             c2t1d0   ONLINE       0     0     0
>             c2t2d0   ONLINE       0     0     0
>             c2t3d0   ONLINE       0     0     0
>             c2t4d0   ONLINE       0     0     0
>           raidz1-1   ONLINE       0     0     0
>             c2t5d0   ONLINE       0     0     0
>             c2t6d0   ONLINE       0     0     0
>             c2t7d0   ONLINE       0     0     0
>             c2t8d0   ONLINE       0     0     0
>             c2t9d0   ONLINE       0     0     0
>           raidz1-3   ONLINE       0     0     0
>             c2t12d0  ONLINE       0     0     0
>             c2t13d0  ONLINE       0     0     0
>             c2t14d0  ONLINE       0     0     0
>             c2t15d0  ONLINE       0     0     0
>             c2t16d0  ONLINE       0     0     0
>             c2t17d0  ONLINE       0     0     0
>             c2t18d0  ONLINE       0     0     0
>             c2t19d0  ONLINE       0     0     0
>             c2t20d0  ONLINE       0     0     0
>             c2t21d0  ONLINE       0     0     0
>             c2t22d0  ONLINE       0     0     0
>             c2t23d0  ONLINE       0     0     0
>           raidz1-4   ONLINE       0     0     0
>             c2t24d0  ONLINE       0     0     0
>             c2t25d0  ONLINE       0     0     0
>             c2t26d0  ONLINE       0     0     0
>             c2t27d0  ONLINE       0     0     0
>             c2t28d0  ONLINE       0     0     0
>             c2t29d0  ONLINE       0     0     0
>             c2t30d0  ONLINE       0     0     0
>           raidz1-5   ONLINE       0     0     0
>             c2t31d0  ONLINE       0     0     0
>             c2t32d0  ONLINE       0     0     0
>             c2t33d0  ONLINE       0     0     0
>             c2t34d0  ONLINE       0     0     0
>             c2t35d0  ONLINE       0     0     0
>             c2t36d0  ONLINE       0     0     0
>             c2t37d0  ONLINE       0     0     0
>           raidz1-6   ONLINE       0     0     0
>             c2t38d0  ONLINE       0     0     0
>             c2t39d0  ONLINE       0     0     0
>             c2t40d0  ONLINE       0     0     0
>             c2t41d0  ONLINE       0     0     0
>             c2t42d0  ONLINE       0     0     0
>             c2t43d0  ONLINE       0     0     0
>             c2t44d0  ONLINE       0     0     0
>         spares
>           c5t10d0    AVAIL
>           c5t11d0    AVAIL
>           c2t45d0    AVAIL
>           c2t46d0    AVAIL
>           c2t47d0    AVAIL
>
>
>
> # iostat -En
>
> c4t0d0           Soft Errors: 0 Hard Errors: 5 Transport Errors: 0
> Vendor: iDRAC    Product: Virtual CD       Revision: 0323 Serial No:
> Size: 0.00GB <0 bytes>
> Media Error: 0 Device Not Ready: 5 No Device: 0 Recoverable: 0
> Illegal Request: 1 Predictive Failure Analysis: 0
> c3t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
> Vendor: iDRAC    Product: LCDRIVE          Revision: 0323 Serial No:
> Size: 0.00GB <0 bytes>
> Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
> Illegal Request: 0 Predictive Failure Analysis: 0
> c4t0d1           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
> Vendor: iDRAC    Product: Virtual Floppy   Revision: 0323 Serial No:
> Size: 0.00GB <0 bytes>
> Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
>
>
> root at host:~# fmadm faulty
> --------------- ------------------------------------  --------------
> ---------
> TIME            EVENT-ID                              MSG-ID
> SEVERITY
> --------------- ------------------------------------  --------------
> ---------
> Jan 05 08:21:09 7af1ab3c-83c2-602d-d4b9-f9040db6944a  ZFS-8000-HC
> Major
>
> Host        : host
> Platform    : PowerEdge-R810
> Product_sn  :
>
> Fault class : fault.fs.zfs.io_failure_wait
> Affects     : zfs://pool=test
>                   faulted but still in service
> Problem in  : zfs://pool=test
>                   faulted but still in service
>
> Description : The ZFS pool has experienced currently unrecoverable I/O
>                     failures.  Refer to
> http://illumos.org/msg/ZFS-8000-HCfor
>               more information.
>
> Response    : No automated response will be taken.
>
> Impact      : Read and write I/Os cannot be serviced.
>
> Action      : Make sure the affected devices are connected, then run
>                     'zpool clear'.
> _______________________________________________
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>
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>


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