Disk thruput

[Wim Van den Wyngaert]

I would like to measure disk thruput per disk(in MBytes), if possible split in Read and Write thruput.

I don't want a program and I don't want to depend on a product like pa. Just DCL and e.g. SDA.

How can I do that ?

[Ian Miller.]

what sort of disks? If an HSx controller is involved then they have programs for that sort of info.

[labadie_1]

I am a bit puzzled: why not a program ?

You have on the freeware various tools

http://h71000.www7.hp.com/freeware/freeware40/disk_balance/

http://h71000.www7.hp.com/freeware/freeware40/disk_monitor/

http://h71000.www7.hp.com/freeware/freeware60/diskblock058/

which should help you.

regards

Gerard

[Wim Van den Wyngaert]

Ian : all kind of disks. Directly attached, MSCP, HSG80, ...
Labadie : I don't want to install things. Just use naked VMS and DCL.

[Hein van den Heuvel]

You can not get there from here.
VMS does not have this.
The closest you can get is possibly to
just time a COPY from a large file.
Large files can be created by sysgen,
by create/fdl ... allocation xxx, or my favourite $copy nl: /cont/alloc
Unfortunatly VMS does not have 'dd' (actually... looked in the posix area? ) nor does it have a /dev/zero, only /dev/null so for write tests you'll need to create a large empty file first... or just use a pagefile as input.

- Watch out for 'high-water-marking' when testing IO.

Good luck,
Groetjes,
Hein.

[Ian Miller.]

have a look at what MONITOR can do - there may be something you can use to calculate but I don't remember anything specific.

[John Eerenberg]

There is a way to get the thruput from DCL but you have to know the typical IO size.

I have several disks dedicated to a database. I know the IO size is 8192 bytes.

$ iocnt1=F$GetDvI("$1$dgannn:","opcnt")
$ wait 00:00:10
$ iocnt2=F$GetDvI("$1$dgannn:","opcnt")
$ kbsec=(iocnt2-iocnt1)*8

kbsec holds the number of KB/Sec for the disks I know the typical IO size. This is a rough number, but at least I get an idea of what is going on.

This can be customized for backup as well if you have a handful of large files (i.e., several GB each) a control-T will tell you the input block size. Very rough though, but it gives you an order of magnitude on the thruput.

Finally this will work if you know the average IO size over a period of time for a disk with a not so cut and dried IO size.

Other then that, no way VMS DCL can give you the info you want.

hope it helps.

[labadie_1]

Ian, may be you were thinking about hyperspi++ ?

http://www.pi-net.dyndns.org/hyperspi++

[Ian Miller.]

as the great Steve Hoffman often says 'what problem are you trying to solve?'
Why did you whant disk thoughput figures - do you think you have a problem or are you doing a capacity planning excersise?

[John Eerenberg]

Oops...
make that Bytes/Second instead of kbsec
$ bsec=((iocnt2-iocnt1)*8192)/10