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lun stats queue_depth_lun counter

bsti
3,581 Views

Hello,

  One of the counters returned by a "stats show lun" is "queue_depth_lun".  The description would lead me to believe it's exactly what it claims it is:  The queue depth of the LUN.  However, the data it returns doesn't make any sense.  In my case, it returns a very high number (in the hundres of millions).  My belief is that this is a raw statistic, and needs to have it's previous value subtracted from it to get it's real value.  Despite doing this, the value still doesn't make any sense.  For instance, I get these values:

(These are the actual values returned by the "stats" command:)

minute 1: 1593764771
minute 2:1593767935
minute 3:1593771165

minute 4:1593818855
minute 5:1593876652
minute 6:1593937485

(These are "delta" values I get when I subtract the raw value from the previous minute's raw value)

minute 1: 3176.0000
minute 2: 3164.0000
minute 3: 3230.0000
minute 4: 47690.0000
minute 5: 57797.0000
minute 6: 60833.0000

The odd thing is the first 3 data points are from when I'm running heavy I/O testing to the LUN, and the second 3 are when it's idle.  Clearly, it doesn't make sense for the queue depth to be higher when idle.

Can anyone tell me if there is another place I should be looking to get queue depth for a LUN?  If not, is this the correct counter?  If so, what am I doing wrong?

I'm running ONTAP 8.0.1P2 on a new HA pair of 6280s.

Thanks!

1 ACCEPTED SOLUTION

hains
3,581 Views

Hello,

You can get LUN "Queue Length" using this command :

lun stats -o -i 1 -c 1

-o = Extra stats

-i = Interval

-c = Count

Read Write Other QFull   Read  Write Average   Queue     Partner  Lun

  Ops   Ops   Ops              kB     kB   Latency   Length       Ops     kB

Jay

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2 REPLIES 2

hains
3,582 Views

Hello,

You can get LUN "Queue Length" using this command :

lun stats -o -i 1 -c 1

-o = Extra stats

-i = Interval

-c = Count

Read Write Other QFull   Read  Write Average   Queue     Partner  Lun

  Ops   Ops   Ops              kB     kB   Latency   Length       Ops     kB

Jay

bsti
3,581 Views

Thanks for the reply.  That will have to do.  I wish the "stats" command returned a usable number though.

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