[HECnet] MONITOR DISK - Meaning of values

[Brian Schenkenberger, VAXman-]

Sampsa Laine <sampsa at mac.com> writes:

>On 16 Sep 2015, at 11:46, Brian Schenkenberger, VAXman- =
><system at TMESIS.COM> wrote:
>
>> Sampsa Laine <sampsa at mac.com> writes:
>>=20
>>> I'm running a batch job that is creating a large (82 GB) file and =3D
>>> monitoring the system with MONITOR DISK.
>>>=20
>>> The value I'm getting is 39 - what does this actually mean, what is =
>the =3D
>>> unit that is being monitored?
>>=20
>>=20
>> I'm assuming you did not specify /ITEM.  =46rom the MONITOR HELP:
>>=20
>>    When the /ITEM qualifier is omitted, the default is =
>/ITEM=3DOPERATION_RATE.
>> 	:
>> 	:
>>       OPERATION_    Specifies that I/O operation rate statistics are
>>       RATE          displayed for each disk.
>>=20
>> What's you concern, if any?
>
>Yes, I did this but the operation rate does not give me an indication of =
>how many block/second are beyond read/written, or does it?

It's a performance metric that is maintained in/by VMS about the number of I/O
operations to the disks.  Maintaining block counts would be more/only meaning-
ful on a per-disk basis.  That's generally not something that's a performance
metric.

This is a very simple procedure to get you a block/second count.  Put this in
a file (BLOCKS_PER_SECOND.COM, for example) and execute it with the disk name
in question. (ie. $ @BLOCKS_PER_SECOND DKA100)

$ 100$:	BLOCKS_THEN = F$getdvi(P1,"FREEBLOCKS")
$	WAIT ::01
$	WRITE SYS$OUTPUT BLOCKS_THEN-F$getdvi(P1,"FREEBLOCKS")	! THEN - NOW
$	GOTO 100$


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