Re: AIX Memory and Paging Space
From: Damir Delija (ddelija_at_PUBLIC.SRCE.HR)
Date: 05/14/05
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Date: Sat, 14 May 2005 06:04:42 +0200 To: aix-l@Princeton.EDU
Since AIX5 can do sizedown on swap oversized swap really is not a
problem, same with too small swap.
If you have enough disk space
RMC can detect swap situations and dynamically upsize it
trough a script. I've done both as acceptacne test
on aix 5.2
so it is quite self correctable.
Damir
On Fri, May 13, 2005 at 12:33:03PM +0200, Holger.VanKoll@SWISSCOM.COM wrote:
> just one advantage and one disadvantage of a big "oversized" ps
>
> disadvantage: (cheap) diskspace wasted
> advantage: more time to react if an application starts to use much
> paging-space
> f.e. I prefer to have 4GB ps and get a warning when its 50% full (2gb
> used) than to have 2GB and get a warning when its 99/100% full
>
>
> >AIX will use the amount of memory solicited by your processes
> in rare cases processes demand real memory, they request the os to pin
> it (plock()). then, this statement is true for those processes.
> in all other cases processes demand only virtual memory and aix is free
> to put it in real mem or paging-space
>
>
>
>
> ________________________________
>
> From: IBM AIX Discussion List [mailto:aix-l@Princeton.EDU] On Behalf Of
> Green, Simon
> Sent: Friday, May 13, 2005 12:13 PM
> To: aix-l@Princeton.EDU
> Subject: Re: AIX Memory and Paging Space
>
>
> It's not possible to say that the paging space is oversized from the
> information available. If you allocate the minimum permitted paging
> space - required for the system to boot - but do no paging at all it
> will appear about 5% used. That's due to the LVM overhead and a small
> amount of data that goes in there at boot time.
>
> If the %used was 1% I might guess it was oversized; otherwise you'd have
> to know what the size really was. The original post does not suggest
> that this is the case.
>
> --
>
> Simon Green
>
> Altria ITSC Europe s.a.r.l.
>
>
>
> AIX-L Archive at https://new-lists.princeton.edu/listserv/aix-l.html
>
> New to AIX? http://publib-b.boulder.ibm.com/redbooks.nsf/portals/UNIX
>
>
>
> N.B. Unsolicited email from vendors will not be appreciated.
>
> Please post all follow-ups to the list.
>
> -----Original Message-----
> From: IBM AIX Discussion List [mailto:aix-l@Princeton.EDU] On
> Behalf Of hercom
> Sent: 13 May 2005 05:45
> To: aix-l@Princeton.EDU
> Subject: Re: AIX Memory and Paging Space
>
>
>
>
>
> Paging space use will be very low: 5% is about right--> A paging
> space so little used seems to be oversized. In general, the paging space
> should be under 40%, and the size must be determined accordingly to the
> application running (i.e. 4X the physical memory size for oracle). In
> AIX 5L a paging space can be reduced without rebooting. Anyway, AIX
> always uses some paging space, even keeping copies of the data on memory
> and on disk, as a "predictive" paging.
>
>
>
- Previous message: jeff barratt-mccartney: "Re: Adding Expansion Unit to DS4300 Turbo"
- In reply to: Holger.VanKoll_at_SWISSCOM.COM: "Re: AIX Memory and Paging Space"
- Next in thread: Green, Simon: "Re: AIX Memory and Paging Space"
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