Latency at the Pool level (view it?)

[SMnasMAN]

Is there anyway to see (or pull) IO latency at the pool level? (or even pending IO requests / disk "busy" stats)

(i know there are deep/excellent stats in the FN gui via NetData and "Reporting" - but each are on the individual disk level).
(i also, almost always, keep gstat running in a ssh session off to the side of my screen - great data, but again is at individual disk level).

thanks!

 

[sretalla]

zpool iostat may be a good place to start...

zpool iostat -v gives you the disk view also.

 

[SMnasMAN]

thanks, i use zpool iostat quite often, but as far as i can tell that only gives you bandwdith usage numbers for pools (not latency numbers for the pools). The -l flag does not work (which i read somewhere is for latency).

Code:

root@freenas:~/SMARTtestMINUShpHUS # zpool iostat -l
invalid option 'l'
usage:
        iostat [-v] [-T d|u] [pool] ... [interval [count]]
root@freenas:~/joSMARTtestMINUShpHUS # zpool iostat -l 2 2
invalid option 'l'
usage:
        iostat [-v] [-T d|u] [pool] ... [interval [count]]
root@freenas:~/SMARTtestMINUShpHUS #


zpool iostat -v 2 50

                                           capacity     operations    bandwidth
pool                                    alloc   free   read  write   read  write
--------------------------------------  -----  -----  -----  -----  -----  -----
HOTspare8TBtrash                        6.52T   748G     21     12  4.70M   213K
  gptid/644b9713-dfc0-11e9-bae4-00259084f1c8  6.52T   748G     21     12  4.70M   213K
--------------------------------------  -----  -----  -----  -----  -----  -----
freenas-boot                            1.33G  54.2G      1     30  20.5K   266K
  mirror                                1.33G  54.2G      1     30  20.5K   266K
    ada0p2                                  -      -      0      9  11.6K   266K
    ada1p2                                  -      -      0     10  10.9K   266K
--------------------------------------  -----  -----  -----  -----  -----  -----
he5x8TBz1                               13.2T  22.6T    106     60  13.2M   519K



root@freenas:~/SMARTtestMINUShpHUS # zpool iostat
                    capacity     operations    bandwidth
pool             alloc   free   read  write   read  write
---------------  -----  -----  -----  -----  -----  -----
HOTspare8TBtrash  6.52T   748G     21     12  4.70M   213K
freenas-boot     1.33G  54.2G      1     30  20.5K   266K
he5x8TBz1        13.2T  22.6T    106     60  13.2M   519K