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Your opinion on tape device performance we could display

marie-noelle jeanson_1
Trusted Contributor

Your opinion on tape device performance we could display

Hi,

HP is seeking your input as to what tape device performance it would be most useful to display in sar (see sar(1M)), apart from the following:
- bytes/sec
- avserv (average time to service each transfer request)
- read/sec
- write/sec

Please add to the above list and specify why it would be important to have these performace data available (how you would use it).

Thanks,

Marie-Noelle (points for all useful answers!)
8 REPLIES
Florian Heigl (new acc)
Honored Contributor

Re: Your opinion on tape device performance we could display

I'll be all happy the values You listed, they'd be in for some nice html reporting data ;)
yesterday I stood at the edge. Today I'm one step ahead.
Kurt Beyers.
Honored Contributor

Re: Your opinion on tape device performance we could display

Marie-Noelle,

Your basic speed values are sure interesting;

Other values that cross my mind are:

How much hardware compression is achieved?
How long was the tape drive idle during the tape session?
How much tape space was lost because the drive was not kept on feeding with data?
How much tape speace is left?

regards,
Kurt
Ivan Ferreira
Honored Contributor

Re: Your opinion on tape device performance we could display

Can errors be detected "on the fly"?. Like netstat ouput output packets and output errors.

In a multi drive tape library, would help if you can see the balanced utilization of the drives.
Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
Florian Heigl (new acc)
Honored Contributor

Re: Your opinion on tape device performance we could display

Kurt:

- The amount of hardware compression will be hard to check on as it takes place somewhere behind the drives' buffers
- as far as I can tell, we poor HP-UX users don't get any hardware compression unless we enable it either via forcing it on the drive or mksf'ing a non-standard special file.
yesterday I stood at the edge. Today I'm one step ahead.
Alexander M. Ermes
Honored Contributor

Re: Your opinion on tape device performance we could display

Hi there.
Your ideas are really not too bad.
Tape usage would also be a nice thing to have. Online display of idle phases ( reason maybe small files or a slow network ) could also help.
Brgds
Alexander M. Ermes
.. and all these memories are going to vanish like tears in the rain! final words from Rutger Hauer in "Blade Runner"
Mahesh Kumar Malik
Honored Contributor

Re: Your opinion on tape device performance we could display

Hi

Based on various inputs, it will be a good idea to display tape drive health e.g. good,average or poor.

Regards
Mahesh
Mark Poeschl_2
Honored Contributor

Re: Your opinion on tape device performance we could display

Hello Marie-Noelle -

Maybe this is implied in your initial post, but read bytes/sec and write bytes/sec in addition to read/sec and writes/sec would be useful. And let me second (or third) the request for some indicator of how much tape remains.
Marino Meloni_1
Honored Contributor

Re: Your opinion on tape device performance we could display

I do not know sar, but if it is an online tool, then it would be usefull to know at what transfer rate the scsi communication took place, and also the mode (LVD / SE)
This for a troubleshooting point of view.
Another parameter would be nice to know online is: if the drive is shoesshining or in case of Ultrium, the ATS is taking place, reducing the performance due to problem with the source of the data.