VMSERVx machines
are CMS. They are in the list of those who cannot use it. They can benefit from
having space allocated for MDC; however, it is probably better to have MDC
allocated from main storage rather than XSTORE.
There are
few operating systems that benefit from XSTORE, any flavor of VM being
principal among them. I do not know whether VSE can use XSTORE, but you can add
CMS, TPF and GCS to the list of non-users.
Regards,
Richard Schuh
-----Original Message-----
From: The IBM z/VM Operating
System [mailto:[EMAIL PROTECTED]On
Behalf Of Steve Gentry
Sent: Tuesday, October 24, 2006
12:05 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: Extended storage
question.
You are correct, DASD paging is near
0.
"The only reason to attach XSTORE to a user is if that user can
actually do something with it."
So, are you saying that DB2,
VMSERVS, VMSERVU, etc, need to have some XSTORE attached to
them so that they will use it? On
our system, these users have a USER DIRECTORY with a MACHINE TYPE XC
Steve
|
|
Marty
Zimelis <[EMAIL PROTECTED]>
Sent by: The IBM
z/VM Operating System <IBMVM@LISTSERV.UARK.EDU>
10/24/2006 10:03 AM
Please respond to
The IBM z/VM Operating System
|
To: IBMVM@LISTSERV.UARK.EDU
cc:
Subject: Re: Extended storage question.
|
Steve,
It sounds like you're a little
confused about what Q XSTORE [MAP] reports. In your current situation,
you correctly point out that no XSTORE is attached to any user. What this
means is that it's all available to CP for its two uses: primary page space and
minidisk cache (MDC). Judging from the third line of the result of Q
XSTORE, you have MDC shut off for your system. Thus, all of XSTORE is
available as page space. The demands of your system are such that only
21% of the available 4608M are needed. (I suspect that your DASD paging
rate is at or near 0.)
The only reason to attach XSTORE to
a user is if that user can actually do something with it. A CMS-based
application cannot. Nor can z/OS these days. My ignorance of VSE is
complete enough that I don't know if it can use XSTORE either.
The only additional information that
Q XSTORE MAP gives you is to show *which* pieces of XSTORE are attached to
users, thus telling you what the largest remaining contiguous chunk is.
It does not (as you seemed to assume) tell you whose pages are in the CP
area used for page space. That information is available in the Monitor
data.
Marty
____________________
Martin Zimelis
Principal
maz/Consultancy
From: The IBM z/VM Operating
System [mailto:[EMAIL PROTECTED] On
Behalf Of Steve Gentry
Sent: Tuesday, October 24, 2006 11:02 AM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Extended storage question.
I trying to figure out what information I'm getting when I issue the Q XSTORE MAP command.
My current XSTORAGE is setup as follows:
q xstore
XSTORE= 4608M
XSTORE= 4608M userid= SYSTEM usage= 21% retained= 0M pending= 0M
XSTORE MDC min=0M, max=0M, usage=0%
XSTORE= 4608M userid= (none) max. attach= 4608M
I don't have any assigned to a specific user so I assume that the system (cp?)
is in control
of it and is thus allocating it as it sees fit.
As shown above, 21% is in use. But, who is using it?
I issue the Q XSTORE MAP
command and get the
following:
q xstore map
START SIZE STATUS
%-IN-USE %-UNUSABLE
0M 4608M
CP
21%
0%
I was hoping that it would tell me that userX was using so much, userY
was using so much, etc.
Or does a user show up in the q xstore map when the storage
has been attached to a
specific user? Say for instance I attach 1000M to a
db2 machine/user. Will that userid then
show up in the list generated by the Q XSTORE MAP command? If
this is the case is there
a command that will tell me who
is using XSTORE and how much (either a percentage or a
total amount used).
And should I let the system allocate it or should I issue the attach statement?
I can see using the
attach statement if you absolutely want a user to have a specific amount of XSTORE
because of
a constrained environment. But what about non-constrained?
Thanks,
Steve G.
