Re: Paging space question

From: Bill Verzal (Bill_Verzal@BCBSIL.COM)
Date: Wed Jul 24 2002 - 08:48:29 EDT

So IBM's statement is more of a "performance" consideration, versus a
"limitation". Or so it would appear.

Thanks, Bill.

-----------------------------------------------------------------------------------------------------------

Bill Verzal
Technical Consultant
Forbes Technical Consulting
(312) 653-3684
bill_verzal@bcbsil.com
MailStop: 27.201C

                    Jeff Barratt
                    <jbarratt@COMP To: aix-l@Princeton.EDU
                    SAT.COM> cc:
                    Sent by: IBM Subject: Re: Paging space question
                    AIX Discussion
                    List
                    <aix-l@Princet
                    on.EDU>

                    07/24/2002
                    06:27 AM
                    Please respond
                    to IBM AIX
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I do not believe this is true(although I believe it was at one time):

here is a test scenario I have created:

# lsps -a
Page Space Physical Volume Volume Group Size %Used Active Auto
Type
paging00 hdisk0 rootvg 8MB 20 yes yes
lv
hd6 hdisk1 rootvg 32MB 1 yes yes
lv
paging02 hdisk1 rootvg 128MB 39 yes yes
lv
paging01 hdisk4 veritasvg 2048MB 3 yes yes
lv

as paging00 is the smallest paging space, no other paging space should use
more than 8MB.

paging02 is using 39% of 128MB which is roughly 50MB. which is greater than
either paging00 or hd6.

paging01 is using 3% of 2048MB which is roughly 61MB. which is greater than
either paging00, hd6, or paging02.

I think this concept (along with the set paging space to 2X RAM, or any
other bizarre allocation based on physical memory size) is no longer
applicable

-----Original Message-----
From: IBM AIX Discussion List [mailto:aix-l@Princeton.EDU]On Behalf Of
Bill Verzal
Sent: Tuesday, July 23, 2002 4:10 PM
To: aix-l@Princeton.EDU
Subject: Paging space question

I am assisting a DBA with troubleshooting a system (SP node, AIX 4.3.3 ML
10). I wish to make a statement to management, but I want to confirm it
first...

Can anyone confirm the following statement for me (and provide resources) ?

"If you have a system with more than one paging space, and they happen to
be different sizes, the system will not use any of the larger paging
space(es) beyond the size of the smaller"

For example

System A has 3 paging spaces configured as follows:

     1024MB
     512MB
     2048MB

AIX will not use more than 512MB of ANY of the paging spaces.

Is this true ? I recall that it is (or was at one time).

Thanks!

----------------------------------------------------------------------------

-------------------------------

Bill Verzal
Technical Consultant
Forbes Technical Consulting
(312) 653-3684
bill_verzal@bcbsil.com
MailStop: 27.201C

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