Yes, We have a Guest user ID(DASDSHR) which owns all shared DASD using Full Pack MDISK statement like the below.
Ex) MDISK 0A10 3390 DEVNO 0A10 MWV
MDISK 0A11 3390 DEVNO 0A11 MWV
MDISK 0A12 3390 DEVNO 0A12 MWV
And three OS/390 guest users link the Full PAck MDISK with MW option.
Ex) LINK SE02 0A10 0A10 MW
LINK SE02 0A11 0A11 MW
LINK SE02 0A12 0A12 MW
Regards
Tae Min Baek
Mmaa Bldg, 467-12 Dogok-Dong
Advisory IT Architect
Seoul, 135700
z/Linux Team
Korea
IBM Sales & Distribution, STG Sales
Phone:
+822-3781-8224
Mobile:
+82-010-4995-8224
e-mail:
tmb...@kr.ibm.com
From: "Davis, Larry (National VM/VSE Capability)" <larry.dav...@hp.com>
To: IBMVM@LISTSERV.UARK.EDU
Date: 2010-05-18 오후 08:11
Subject: Re: Batch job takes too long in OS/390 Guest under z/VM
v6.1
Sent by: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU>
Do you have a single ID that owns all the shared DASD using Full Pack
MDISK statements using the MWV Mode, and do all the z/OS guest link to
these disks using just MW?
Or do all the z/OS guest have the FP MDISK statements with the MWV mode?
Larry Davis
From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On
Behalf Of TaeMin Baek
Sent: Monday, May 17, 2010 10:49 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: Batch job takes too long in OS/390 Guest under z/VM v6.1
The change is that we add xstor 1GB and the others are same.
we reduced the number of ESCON Channel from 16 to 8 and now channel busy
is around 50%~70%.
We are sharing DASD among 5 OS/390 Virtual Machines by Using Virtual
Reserve/Release(MWV Option for MDISK) with SET SHARED ON option in SYSTEM
CONFIG.
I read 'CP pllaning and admin guide and it says like the below.
*When to Use Concurrent Virtual and Real Reserve/Release
In general, you should use concurrent virtual and real reserve/release
when you need to share DASD among many virtual machines and other systems.
Do not use this method when you need to share DASD only among virtual
machines, because the CP overhead is much greater than if you use virtual
reserve/release.
If I changed the option to 'SET SHARED OFF', can it reduce CP overhead
between VM Guest OS?
and is it safe to change this option by SET command while system is
running?
Regards
Tae Min Baek
Mmaa Bldg, 467-12 Dogok-Dong
Advisory IT Architect
Seoul, 135700
z/Linux Team
Korea
IBM Sales & Distribution, STG Sales
Phone:
+822-3781-8224
Mobile:
+82-010-4995-8224
e-mail:
tmb...@kr.ibm.com
From: Marcy Cortes <marcy.d.cor...@wellsfargo.com>
To: IBMVM@LISTSERV.UARK.EDU
Date: 2010-05-18 오전 09:13
Subject: Re: Batch job takes too long in OS/390 Guest under z/VM
v6.1
Sent by: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU>
What changes were made to your memory config? xstor, cstor, mdc size ?
Any changes to the I/O configuration?
Marcy
"This message may contain confidential and/or privileged information. If
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________________________________
From: The IBM z/VM Operating System [mailto:ib...@listserv.uark.edu] On
Behalf Of TaeMin Baek
Sent: Monday, May 17, 2010 3:22 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: [IBMVM] Batch job takes too long in OS/390 Guest under z/VM v6.1
We migrate three OS/390 system from 2064-2C1 running on native LPAR mode
to 2098-T01 running
under z/VM like the below.
HW: z10 BC- 2098 T01 (GCP 1 EA)
OS: z/VM V6.1
Guest OS: Four OS/390 v2.10 (SE02, SE05, SE06, CF) running under z/VM
1) Between three OS/390 guests share many DASD which are defined by
full-pack minidisk in CP
directory.
2) three OS/390 guests share the DASD using GRS. MIM is used before
migration
3) three OS/390 guests are coupled by Sysplex(VCFLINK under z/VM) thru CF
guest
4) Sysplex(XCF) is used for only GRS and Tape sharing. MIA is used before
migration
5) GRS was not used befor migration
* Problem Symptom
=> During night time, batch job workload on SE02 was taking too long and
SE02 Guest system
has high CPU usage(Specially Supervisor CPU% is high around 32% and
Emulated CPU% is 35%) and I/O wait(12%) by performance toolkit.
=> By monitoring in OS/390(SE02), CPU Usage of MASTER, GRS, CATALOG task
is high. therefore batch job is hard to get CPU resource.
=> CF Guest user has only 1% of CPU utilization.
=> batch job use DASD and Tape devices.
could it be caused by VM side or OS/390?
What do we need to check more to find what is root cause and to fix this
problem?
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