The built-in default system limit is the minimum of:
* The amount of virtual storage that can be represented by
one-quarter of the usable dynamic paging area (DPA), based on the fact
that each gigabyte of virtual disk defined requires 2050 frames of host
real storage
* The amount of storage represented by one-quarter of the paging
space defined for CP use
-----Original Message-----
From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On
Behalf Of Schuh, Richard
Sent: Wednesday, April 07, 2010 11:17 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: V-disk
The question was not for a system that hosts Linux guests, it is for one
that uses V-disk instead of T-disk for most temp space. The doc mentions
DPA < 2G, DPA and external page space, but I don't see any formula for
calculating the SYSLIM that would be the default if none were specified
in the SYSTEM CONFIG. The current config file limits were determined in
a galaxy far, far away at a time long, long ago. I was wondering how
they would compare to the current system defaults which may well be more
generous than the limits that have been set. The problem is, we are as
close to 24X365.25 as we can be, so it may be a long time before I can
bring the system up without the config limits to see.
Regards,
Richard Schuh
> -----Original Message-----
> From: The IBM z/VM Operating System
> [mailto:ib...@listserv.uark.edu] On Behalf Of Barton Robinson
> Sent: Tuesday, April 06, 2010 4:49 PM
> To: IBMVM@LISTSERV.UARK.EDU
> Subject: Re: V-disk
>
> I've looked at a lot of installations using vdisk - I've only
> once seen an installation where vdisk "seemed" to be an issue
> - and that was when the installation had followed the 2 vdisk
> for swap guideline, but reversed the priority on the two
> disks and the larger one was used instead of the small one.
> So unless you've come up with a new imaginative way to use
> vdisk, use "INFINITE" and use the ESAMAP report ESASTR1 to
> understand the cost.
> There are many more important things to work on....
>
> Schuh, Richard wrote:
> > Is there a formula that can be used to determine what the default
> > SYSLIM for V-disks would be in the absence of any SYSTEM CONFIG
> > definitions? If I enter QUERY FRAMES, I get this:
> >
> > q
> > frames
>
> >
> > All
> > Frames:
>
> > Configured=38273023 Real=38273023 Usable=38273023
> > Offline=0
> > Pageable=37871142 NotInitialized=0
> > GlobalClearedAvail=160
> > LocalClearedAvail=160
> > LocalUnclearedAvail=155
> >
> > Frames <
> > 2G:
>
> > GlobalUnclearedAvail=56339 Pageable=513876
> > LogicalFreeStorage=5602
> > RealFreeStorage=5 LockedRS=497
> > LockedCmd=0
> > MinidiskCache=8 Nucleus/Prefix=2521 Trace=400
> > Other=1386
> >
> > Frames >
> > 2G:
>
> > GlobalUnclearedAvail=4046728 Pageable=37357266
> > LogicalFreeStorage=55733
> > RealFreeStorage=19 LockedRS=15358
> > LockedCmd=0
> > MinidiskCache=97600
> > Other=320360
> >
> >
> > Assuming that the dasd space is sufficient to not be a limiting
> > factor, does this give enough information to calculate a
> default SYSLIM?
> >
> > Regards,
> > Richard Schuh
> >
> >
> >
>
