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Re: Performance assistance sought

 
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Jan van den Ende
Honored Contributor

Re: Performance assistance sought

BoyeDave,

from your Forum Profile:


I have assigned points to 3 of 26 responses to my questions.


Maybe you can find some time to do some assigning?

http://forums1.itrc.hp.com/service/forums/helptips.do?#33

Mind, I do NOT say you necessarily need to give lots of points. It is fully up to _YOU_ to decide how many. If you consider an answer is not deserving any points, you can also assign 0 ( = zero ) points, and then that answer will no longer be counted as unassigned.
Consider, that every poster took at least the trouble of posting for you!

To easily find your streams with unassigned points, click your own name somewhere.
This will bring up your profile.
Near the bottom of that page, under the caption "My Question(s)" you will find "questions or topics with unassigned points " Clicking that will give all, and only, your questions that still have unassigned postings.

Thanks on behalf of your Forum colleagues.

PS. - nothing personal in this. I try to post it to everyone with this kind of assignment ratio in this forum. If you have received a posting like this before - please do not take offence - none is intended!

PPS. - Zero points for this.

Proost.

Have one on me.

jpe
Don't rust yours pelled jacker to fine doll missed aches.
BoyeDav
Frequent Advisor

Re: Performance assistance sought

I'll try to be better about assigning points.

Thanks for all the suggestions. We have a support contract with HP, so that's an option I might go with.

In the mean time, I have some digging to do to understand a lot of what everyone is saying. I need to understand alignment faults and how to determine file extent size, etc.
Robert Gezelter
Honored Contributor
Solution

Re: Performance assistance sought

BoyeDav,

As to the RMS settings, the command to show the current settings is SHOW RMS (the command to change the settings is SET RMS). Both commands are documented in the HELP text.

As an example, I generally do the following line in my LOGIN.COM:
$ SET RMS/EXTENT=100000

on the account that I am expecting to write large files from. It is also a good idea in that case to check the growing file from another process to ensure that the file is being extended using the RMS value, and the program does not have its own, hardcoded opinion of how much to extend the file by.

- Bob Gezelter, http://www.rlgsc.com
Karl Rohwedder
Honored Contributor

Re: Performance assistance sought


< As an example, I generally do the following
< line in my LOGIN.COM:
< $ SET RMS/EXTENT=100000

Pls. note that the maximum extend is 65535:

$ set rms/ext=100000
%SET-E-VALERR, specified value is out of legal range

regards Kalle
Colin Butcher
Esteemed Contributor

Re: Performance assistance sought

As someone else pointed out - performance issues are difficult (if not impossible) to assess without actually seeing the system.

Data from collection and visualisation tools such as T4 can help a lot, but it's a case of understanding your workload and seeing all the other things which might be going on that may well be relevant.

I'd encourage you to get some short-term expert help on-site - then work with them and learn from them during the investigation. It's usually a much faster and more effective way to solve problems.

Hope that helps. Cheers, Colin.

Entia non sunt multiplicanda praeter necessitatem (Occam's razor).
BoyeDav
Frequent Advisor

Re: Performance assistance sought

Here is my SHOW RMS output. It's the same as on the old server.
BoyeDav
Frequent Advisor

Re: Performance assistance sought

...and here's what I get showing RMS_EXTEND_SIZE from SYSMAN:

current: 0
min: 0
default: 0
max: 65535

Also the same as on the old server.
Robert Gezelter
Honored Contributor

Re: Performance assistance sought

Karl,

Indeed. The hazard of posting very late at night after a long day. I did not see the extra '0'.

My apologies for the typographical error.

- Bob Gezelter, http://www.rlgsc.com
Volker Halle
Honored Contributor

Re: Performance assistance sought

You did not yet explicitly confirm the workload running on your system at the time when you've been taking the MONITOR samples.

Is my guess true, that you were running BACKUP/IMAGE SYS$SYSDEVICE: DPA11:saveset/SAVE ?

This would explain the DKA3: IO load and the DPA11: IO queue. But if your workload was completely different, these conclusions would just be wrong.

Don't worry about these Alignment Faults yet. You CPUs are mostly idle and Alignment Faults won't cause disk-IOs. 'Huge numbers' of alignment faults look different...

Volker.
BoyeDav
Frequent Advisor

Re: Performance assistance sought

Sorry for the slow response. I've been trying to absorb everything and educate myself a little on all this. To answer some of the questions:

The MONITOR results were done during the day under typical workloads. We use an application called POISE, which I'd call a database application. I used the BACKUP times as an example, but users overall are seeing slowness.

For backups, we're using BACKUP/IGNORE=INTERLOCK since we're not backing up the whole volumes. Our system analysts will sometimes archive database copies locallay for a couple weeks after major changes, and we don't back up those archives nightly. Including those would add about 15% to our backup size. Would the performance benefits of /IMAGE be worth it?

I've added $SET RMS/EXTEND=50000 to the begining of my backup script. I've added this to SYLOGIN.COM:

$ set rms/seq/block=127/buff=8
$ set rms/ind/buf=20
$ set rms/extent=4096

Also, I've been informed that the SAS1068 controller that shipped with our rx3600 has no onboard cache. Not sure to what extent that makes a difference. I come from an x86 background, and this is the first time I've dealt with an "enterprise" controller that didn't have some type of cache.