Hi Kris,

it seems to be dasd paging, because there is also heavy i/o on one paging
dasd. I have found your "data in memory techniques" document, but there is
no exec for checking ind spaces only qnssmap exec is listed there. But it
was a good hint. I have created a small exec which does the ind spaces user
xxx every minute and writes the result with a timestamp into a file. This I
will let the customer run a few hours and check the results. I will not
parse the command now because I have zVM 5.2 and I'm not sure if the command
output is the same on VM/ESA 2.2. If I have the results available I will
contact you again.

regards

Franz Josef

----- Original Message ----- 
From: "Kris Buelens" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, December 12, 2006 3:44 PM
Subject: Re: [IBMVM] problem with an old vm/esa environment after migration
to a flex-es tserver


Do you know if this paging is "real paging" or "Dataspace I/O": when using
VM dataspace support in DB2, all DB2 I/O is done by CP paging, hence high
page rates.

Quite some years ago, I created  a document  to explain the difference. It
is called "Data in  memory techniques" or alike and available on the VM
web page.
If you search for EXECLOAD, NUCXLOAD and, BUELENS  you should quickly find
it back.  It contains an EXEC that you can run in a server every x minutes
and that then will report how many real page in/out happend and how many
dataspace read/writes (based on counts reported by CP IND SPACES)

If you've got RTM/ESA, its DISPLAY SYSDASD command also reports the
dataspace "paging I/O"

Kris,
IBM Belgium, VM customer support




"Pohlen (Mailinglist)" <[EMAIL PROTECTED]>
Sent by: The IBM z/VM Operating System <[email protected]>
2006-12-12 14:54
Please respond to
The IBM z/VM Operating System <[email protected]>


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Subject
problem with an old vm/esa environment after migration to a flex-es
tserver





Hi listers,

I have a customer with a really old VM/ESA 2.2, VSE/ESA 2.3 and SQLDS
database. Now after migration to the tserver he complains about
performance
problems. What I have figured out that he has massive paging only on SQLDS
service machine (300-500 pages/s). This I cannot understand, because first
he has more memory available as before on multiprise (193 MB vs. 768 MB
now)
and second we haven't changed the system layout compared to the
multiprise.
We have migrated the system by dump/restoring the volumes with DDR. So
what
can cause only the sqlds machine to page so heavily? I have already
doubled
the virtual memory to 96 MB but this had no effect on the behaviour. Does
anybody have an idea, where I can search for the problem?

Mit freundlichen Grüßen / best regards

Franz Josef Pohlen

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