speed up backups

[Peter Zeiszler]

I have an openvms 7.3-2 system connected to XP1024 storage via 2 HBA. Disks are balanced between the HBA (half and half - not load balanced - harder to find that out). I am trying to speed up backups that are disk to disk backups.

I have a test file that I am using that is 15gig. It is taking approximately 26 minutes.
I have been changing the backup account, quotas, working set values, etc to see if I can speed this up any.

I have even had a HP VMS person looking at VMS and another checking the storage & SAN with nothing showing as a bottle neck.

Was hoping someone here might have ideas of what else to try.
I have checked out page on hoffmanlabs site. Tried those quotas.

Currently the account is:
Fillm: 2032 Bytlm: 556768
Shrfillm: 0 Pbytlm: 0
BIOlm: 2032 JTquota: 4096
DIOlm: 6096 WSdef: 1024
ASTlm: 6116 WSquo: 75000
TQElm: 200 WSextent: 100000
Enqlm: 2034 Pgflquo: 1074048

[Robert Gezelter]

Peter,

What is the command line that is being used? Is the output a save set?

If it is, check the increment that it is extending.

- Bob Gezelter, http://www.rlgsc.com

[Peter Zeiszler]

Basic command
backup disk:[dir]file.img scratch1:[dir]file.img

Not save set.

[Peter Zeiszler]

FYI - Initial file is only 2 extents. So not a fragmented file.

[Hein van den Heuvel]

>> 15gig. It is taking approximately 26 minutes

So that's just 10mb/sec. Not much!

Speaking of not tot much, I don't have much time today, so just a few quick hints.

> DIOlm: 6096 WSdef: 1024
> ASTlm: 6116 WSquo: 75000

Those are pretty ridiculous 'limits' and Backup will try to use them, and scare the living daylights out of the storage system cache controller and fibre channel arbitration control for the queue depth.

The backup folks have finally also realized that and throttled down some.
On 8.3 there is the /IO_LOAD to throttle it down to say 4 or 8.

If that switch did not make it to 7.3-2 then I would recommend a re-test with DIOLM = 10, just for grins. (check PQL minimums).

Google for FC queue depth topics like:
http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=1143614

There were some OpenVMS driver issues where the back-off / ramp-up mechanisme was broken. Once you were slapped on the wrist, it would go very very slow.

note... I believe that the RMS settings like EXTEND/BLOCK/BUF are only important when creating savesets.

Finally, tries COPY as a baseline?
Again the 8.3 Copy has a nice large block size defaul, and a switch to controll it. Not sure that made it back to 7.3-2. Worth a try!


Good Luck,
Hein/

[Peter Zeiszler]

PQL diolm is 100

I did read up on the io_load capability in the new OS. Unfortunately it will be awhile still before I can upgrade.

From the log file:

Process Quotas:
Account name: SYSTEM
CPU limit: Infinite Direct I/O limit: 100
Buffered I/O byte count quota: 555680 Buffered I/O limit: 2032
Timer queue entry quota: 199 Open file quota: 2030
Paging file quota: 1068208 Subprocess quota: 20
Default page fault cluster: 96 AST quota: 6115
Enqueue quota: 2034 Shared file limit: 0
Max detached processes: 0 Max active jobs: 0

[Peter Zeiszler]

Wish formatting was kept when actually submitting.
Hope this looks better.

[Hein van den Heuvel]

Yeah, attachments with the real data is the way the go in this forum.

it helps a little to check: [x] Retain format(spacing).
(before hitting the submit... I always get that wrong :-)

So create yourself a play account for a while, not system.

That PROCESS QUOTA picture is static right?
Tyr $SHOW PROC/CONT and with the Q character for the dynamic picture... or is that also 8.3 ?
There is always SDA to check behind the scenes.

How much resources did backup use? (IO count, CPU) ?
Can you figure out the IO size and such from there...

[Peter Zeiszler]

the show process/quota is static right before the backup starts.
I then use the quota.com I got from DEC and monitor it.

I had to use a different system in the cluster to modify for pql_mdiolm = 10.

[Peter Zeiszler]

Can play with account quotas. Read up on documents. Linking for references:
http://h71000.www7.hp.com/doc/73final/6017/6017pro_045.html

http://labs.hoffmanlabs.com/node/49