[Gluster-devel] missing files

Pranith Kumar Karampuri pkarampu at redhat.com
Thu Feb 12 09:35:29 UTC 2015


On 02/12/2015 09:14 AM, Justin Clift wrote:
> On 12 Feb 2015, at 03:02, Shyam <srangana at redhat.com> wrote:
>> On 02/11/2015 08:28 AM, David F. Robinson wrote:
>>> My base filesystem has 40-TB and the tar takes 19 minutes. I copied over 10-TB and it took the tar extraction from 1-minute to 7-minutes.
>>>
>>> My suspicion is that it is related to number of files and not necessarily file size. Shyam is looking into reproducing this behavior on a redhat system.
>> I am able to reproduce the issue on a similar setup internally (at least at the surface it seems to be similar to what David is facing).
>>
>> I will continue the investigation for the root cause.
Here is the initial analysis of my investigation: (Thanks for providing 
me with the setup shyam, keep the setup we may need it for further analysis)

On bad volume:
  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of 
calls         Fop
  ---------   -----------   -----------   ----------- 
------------        ----
       0.00       0.00 us       0.00 us       0.00 us 937104      FORGET
       0.00       0.00 us       0.00 us       0.00 us 872478     RELEASE
       0.00       0.00 us       0.00 us       0.00 us          23668 
RELEASEDIR
       0.00      41.86 us      23.00 us      86.00 us 92        STAT
       0.01      39.40 us      24.00 us     104.00 us 218      STATFS
       0.28      55.99 us      43.00 us    1152.00 us 4065    SETXATTR
       0.58      56.89 us      25.00 us    4505.00 us 8236     OPENDIR
       0.73      26.80 us      11.00 us     257.00 us 22238       FLUSH
       0.77     152.83 us      92.00 us    8819.00 us 4065       RMDIR
       2.57      62.00 us      21.00 us     409.00 us 33643       WRITE
       5.46     199.16 us     108.00 us  469938.00 us 22238      UNLINK
       6.70      69.83 us      43.00 us    7777.00 us 77809      LOOKUP
       6.97     447.60 us      21.00 us   54875.00 us 12631    READDIRP
       7.73      79.42 us      33.00 us    1535.00 us 78909     SETATTR
      14.11    2815.00 us     176.00 us 2106305.00 us 4065       MKDIR
      54.09    1972.62 us     138.00 us 1520773.00 us 22238      CREATE

On good volume:
  %-latency   Avg-latency   Min-Latency   Max-Latency   No. of 
calls         Fop
  ---------   -----------   -----------   ----------- 
------------        ----
       0.00       0.00 us       0.00 us       0.00 us 58870      FORGET
       0.00       0.00 us       0.00 us       0.00 us 66016     RELEASE
       0.00       0.00 us       0.00 us       0.00 us          16480 
RELEASEDIR
       0.00      61.50 us      58.00 us      65.00 us 2        OPEN
       0.01      39.56 us      16.00 us     112.00 us 71        STAT
       0.02      41.29 us      27.00 us      79.00 us 163      STATFS
       0.03      36.06 us      17.00 us      98.00 us 301       FSTAT
       0.79      62.38 us      39.00 us     269.00 us 4065    SETXATTR
       1.14     242.99 us      25.00 us   28636.00 us 1497        READ
       1.54      59.76 us      25.00 us    6325.00 us 8236     OPENDIR
       1.70     133.75 us      89.00 us     374.00 us 4065       RMDIR
       2.25      32.65 us      15.00 us     265.00 us 22006       FLUSH
       3.37     265.05 us     172.00 us    2349.00 us 4065       MKDIR
       7.14      68.34 us      21.00 us   21902.00 us 33357       WRITE
      11.00     159.68 us     107.00 us    2567.00 us 22003      UNLINK
      13.82     200.54 us     133.00 us   21762.00 us 22003      CREATE
      17.85     448.85 us      22.00 us   54046.00 us 12697    READDIRP
      18.37      76.12 us      45.00 us     294.00 us 77044      LOOKUP
      20.95      85.54 us      35.00 us    1404.00 us 78204     SETATTR

As we can see here, FORGET/RELEASE are way more in the brick from full 
volume compared to the brick from empty volume. It seems to suggest that 
the inode-table on the volume with lots of data is carrying too many 
passive inodes in the table which need to be displaced to create new 
ones. Need to check if they come in the fop-path. Need to continue my 
investigations further, will let you know.

Pranith
> Thanks Shyam. :)
>
> + Justin
>
> --
> GlusterFS - http://www.gluster.org
>
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>
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