raw filesystem counters

[Eric A. Borisch]

On Tue, Feb 13, 2018 at 1:56 PM, E.S. Rosenberg
<esr+freebsd-fs at mail.hebrew.edu> wrote:
> Wow Eric that is exactly what I was looking for!
> Thanks!
> Nothing similar exists for ZFS correct?
> Thanks again,
> Eli

Here's a quick patch to zpool that adds a "raw" mode when
ZPOOL_RAW_STATS is set (to anything) in the environment. Outputs are
not averaged by time, so the first output has absolute counters from
boot, and subsequent (if provided an interval, eg zpool iostat 5) *are
not* averaged over the period. You could certainly average for
interval but not initial; I just chose to remove all averaging.

https://gist.github.com/eborisch/c610c55cd974b9d4070c2811cc04cd8f

Could also be implemented as a -p (parsable) flag to zpool iostat, but
this was less intrusive to code up.

On my system (with the above patch):

$  zpool iostat

               capacity     operations    bandwidth
pool        alloc   free   read  write   read  write
----------  -----  -----  -----  -----  -----  -----
system      67.2G  13.8G      9     51   159K   879K
tome        2.94T   697G     19     34   949K   645K
----------  -----  -----  -----  -----  -----  -----

$ ZPOOL_RAW_STATS=1 zpool iostat

pool/dev,alloc,free,rops,wops,rbytes,wbytes
system,72199012352,14774075392,42138123,228011166,717996265472,3978917265408
tome,3237433278464,748296372224,87257557,150639839,4293053411328,2918490030080

$ ZPOOL_RAW_STATS=1 zpool iostat -v

pool/dev,alloc,free,rops,wops,rbytes,wbytes
system,72200007680,14773080064,42138142,228019481,717997350912,3979089575936
::gpt/system,72200007680,14773080064,42138142,228019481,717997350912,3979089575936
tome,3237679747072,748049903616,87257714,150656638,4293054717952,2918798745600
::mirror,3237679747072,748049903616,87257682,146824479,4293052755968,2461179686912
::::diskid/DISK-NNNNNNNp1,-,-,49889874,46124191,3718731919360,2468656459776
::::diskid/DISK-NNNNNNNp1,-,-,50357481,45933366,3683843850240,2468656459776
::gpt/log,1875968,2128830464,32,3832159,1961984,457619058688

With an uptime of ~51 days.

Enjoy!
  - Eric