Single file snap restore performance

[borismekler]

FAS2020, single 6x600GB RAID-DP RG aggregate, restoring a VMDK from a snapshot using the following command:

snap restore -t file -s test.1 -r /vol/test1/testvm1_restore/testvm1-flat.vmdk /vol/test1/testvm1/testvm1-flat.vmdk

Typical sysstat -x 10 output is as follows:

CPU   NFS  CIFS  HTTP   Total    Net kB/s   Disk kB/s     Tape kB/s Cache Cache  CP   CP Disk    FCP iSCSI   FCP  kB/s iSCSI  kB/s

                                  in   out   read  write  read write   age   hit time  ty util                 in   out    in   out

64%    16     0     0      28   210    17   7522  12064     0     0    14s  98%  53%  Hf  23%      0    12     0     0     7     0

63%    20     0     0      36   233    25   7834  12750     0     0    21s  98%  57%  Hf  25%      0    16     0     0     9     0

63%    18     0     0      32   238    17   8294  12059     0     0    13s  98%  52%  H   23%      0    14     0     0     9     0

62%    28     0     0      43   209    82   7924  10858     0     0    18s  98%  46%  H   23%      0    15     0     0    11     0

63%    15     0     0      34   245    26   7912  10963     0     0     6s  98%  49%  H   23%      0    19     0     0    13     0

Neither CPU nor disks are saturated - why isn't it running faster? 10-13MB/s for 4x 15k rpm drives is kind of slow.

[aborzenkov]

Single file snap restore performance is miserable.Recently I had to test it on FAS3140 with 2 x 112 disks (SyncMirror). You get as much as 1GB/min (not measured exactly, but just looking at restoed size so far). It is really frustrating.

[nitish]

If you are restoring to a different file, use Snapvault resotre (if you have the license)

Snapvault restore works far far better .......

snap restore to a different file is toooooo slow.

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