>From memory and a study I did 20+ years ago, channel utilization above 30-35 percent is a problem. Keep in mind that was with old fashioned spinning dasd on block mpx channels, but it may still apply. Channel service time increased very gradually up to about 30-35%. There was an exponential curve that tracked service time with the bend in the curve at 30-35% channel utilization. Beyond that point, service time grew very quickly. You may be seeing the same problem with your channel busy time at 50-70%.
Jim Bohnsack On 5/17/2010 10:49 PM, TaeMin Baek wrote: > This is a multipart message in MIME format. > --=_related 000F7A3F49257727_= > Content-Type: multipart/alternative; boundary="=_alternative > 000F7A3F49257727_=" > > > --=_alternative 000F7A3F49257727_= > Content-Type: text/plain; charset="ISO-2022-KR" > > 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 > you are not the addressee or authorized to receive this for the addressee, > you must not use, copy, disclose, or take any action based on this message > or any information herein. If you have received this message in error, > please advise the sender immediately by reply e-mail and delete this > message. Thank you for your cooperation." > > > > ________________________________ > > 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? > > > --=_alternative 000F7A3F49257727_= > Content-Type: text/html; charset="ISO-2022-KR" > > <font size=2 face="sans-serif">The change is that we add xstor 1GB and > the others are same. </font> > <br><font size=2 face="sans-serif">we reduced the number of ESCON Channel > from 16 to 8 and now channel busy is around 50%~70%.</font> > <br> > <br><font size=2 face="sans-serif">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.</font> > <br><font size=2 face="sans-serif">I read 'CP pllaning and admin guide > and it says like the below.</font> > <br> > <br><font size=4><b>*When to Use Concurrent Virtual and Real Reserve/Release > </b></font> > <br><font size=2>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. </font> > <br><font size=2 face="sans-serif"><br> > If I changed the option to 'SET SHARED OFF', can it reduce CP overhead > between VM Guest OS?</font> > <br><font size=2 face="sans-serif">and is it safe to change this option > by SET command while system is running?</font> > <br> > <br><font size=2 face="Arial">Regards</font> > <br> > <table> > <tr> > <td colspan=4> > <hr> > <tr> > <td colspan=4> > <tr> > <td colspan=2><font size=1 face="Arial"><b>Tae Min Baek</b></font> > <td><font size=1 color=#5f5f5f face="Arial"> Mmaa Bldg, 467-12 > Dogok-Dong</font> > <td rowspan=3> > <div align=right><img src=cid:_1_096CBCDC096CB908000F7A3F49257727></div> > <tr> > <td colspan=2><font size=1 color=#5f5f5f face="Arial">Advisory IT > Architect</font> > <td><font size=1 color=#5f5f5f face="Arial"> Seoul, 135700</font> > <tr> > <td colspan=2><font size=1 color=#5f5f5f face="Arial">z/Linux Team</font> > <td><font size=1 color=#5f5f5f face="Arial"> Korea</font> > <tr> > <td colspan=2><font size=1 color=#5f5f5f face="Arial">IBM Sales & > Distribution, > STG Sales</font> > <td><font size=1 color=#5f5f5f face="Arial"> </font> > <td> > <tr> > <td><font size=1 color=#5f5f5f face="Arial">Phone:</font> > <td><font size=1 color=#5f5f5f face="Arial">+822-3781-8224</font> > <td><font size=1 color=#5f5f5f face="Arial"> </font> > <td> > <tr> > <td><font size=1 color=#5f5f5f face="Arial">Mobile:</font> > <td><font size=1 color=#5f5f5f face="Arial">+82-010-4995-8224</font> > <td><font size=1 color=#5f5f5f face="Arial"> </font> > <td> > <tr> > <td><font size=1 color=#5f5f5f face="Arial">e-mail:</font> > <td><font size=1 color=#5f5f5f face="Arial">tmb...@kr.ibm.com</font> > <td><font size=1 color=#5f5f5f face="Arial"> </font> > <td></table> > <br> > <br> > <br> > <br> > <br><font size=1 color=#5f5f5f face="sans-serif">From: > </font><font size=1 face="sans-serif">Marcy Cortes > <marcy.d.cor...@wellsfargo.com></font> > <br><font size=1 color=#5f5f5f face="sans-serif">To: > </font><font size=1 face="sans-serif">IBMVM@LISTSERV.UARK.EDU</font> > <br><font size=1 color=#5f5f5f face="sans-serif">Date: > </font><font size=1 face="sans-serif">2010-05-18 오전 09:13</font> > <br><font size=1 color=#5f5f5f face="sans-serif">Subject: > </font><font size=1 face="sans-serif">Re: Batch job > takes too long in OS/390 Guest under z/VM v6.1</font> > <br><font size=1 color=#5f5f5f face="sans-serif">Sent by: > </font><font size=1 face="sans-serif">The IBM z/VM > Operating System <IBMVM@LISTSERV.UARK.EDU></font> > <br> > <hr noshade> > <br> > <br> > <br><tt><font size=2>What changes were made to your memory config? > xstor, > cstor, mdc size ?<br> > Any changes to the I/O configuration?<br> > <br> > <br> > Marcy <br> > <br> > "This message may contain confidential and/or privileged information. > If you are not the addressee or authorized to receive this for the addressee, > you must not use, copy, disclose, or take any action based on this message > or any information herein. If you have received this message in error, > please advise the sender immediately by reply e-mail and delete this message. > Thank you for your cooperation."<br> > <br> > <br> > <br> > ________________________________<br> > <br> > From: The IBM z/VM Operating System [</font></tt><a > href=mailto:IBMVM@LISTSERV.UARK.EDU><tt><font > size=2>mailto:IBMVM@LISTSERV.UARK.EDU</font></tt></a><tt><font size=2>] > On Behalf Of TaeMin Baek<br> > Sent: Monday, May 17, 2010 3:22 PM<br> > To: IBMVM@LISTSERV.UARK.EDU<br> > Subject: [IBMVM] Batch job takes too long in OS/390 Guest under z/VM v6.1<br> > <br> > <br> > We migrate three OS/390 system from 2064-2C1 running on native LPAR mode > to 2098-T01 running <br> > under z/VM like the below.<br> > <br> > HW: z10 BC- 2098 T01 (GCP 1 EA)<br> > OS: z/VM V6.1<br> > Guest OS: Four OS/390 v2.10 (SE02, SE05, SE06, CF) running under z/VM<br> > <br> > 1) Between three OS/390 guests share many DASD which are defined by full-pack > minidisk in CP <br> > directory.<br> > 2) three OS/390 guests share the DASD using GRS. MIM is used before > migration<br> > 3) three OS/390 guests are coupled by Sysplex(VCFLINK under z/VM) thru > CF guest<br> > 4) Sysplex(XCF) is used for only GRS and Tape sharing. MIA is used before > migration<br> > 5) GRS was not used befor migration<br> > <br> > * Problem Symptom<br> > => During night time, batch job workload on SE02 was taking too > long and SE02 Guest system <br> > has high CPU usage(Specially Supervisor CPU% is high around 32% and Emulated > CPU% is 35%) and I/O wait(12%) by performance toolkit.<br> > => By monitoring in OS/390(SE02), CPU Usage of MASTER, GRS, CATALOG > task is high. therefore batch job is hard to get CPU resource.<br> > => CF Guest user has only 1% of CPU utilization.<br> > => batch job use DASD and Tape devices.<br> > <br> > could it be caused by VM side or OS/390? <br> > What do we need to check more to find what is root cause and to fix this > problem?<br> > </font></tt> > <br> > --=_alternative 000F7A3F49257727_=-- > --=_related 000F7A3F49257727_= > Content-Type: image/gif > Content-ID: <_1_096CBCDC096CB908000F7A3F49257727> > Content-Transfer-Encoding: base64 > > R0lGODlhUwAeALMAAP///wCKvwCz7wA+abLc7H/E33/Z90yt0kzK9LLo+gAAAAAAAAAAAAAAAAAA > AAAAACH5BAAAAAAALAAAAABTAB4AAAT/cMhJKwAi680zMlcIBGRpkmJ6rkEaVjB1dXRnJCJ7Ei5A > 6KaecEgsGo/IpHLJbKZi0FltugGNgCWe6IdF9aAxKXV86ZIKqYK55Wy73/C4XBkedlyGuwqIvqiB > dDBEeiJ5GwguXSGKc42Oj5CRInVCYzY9XQcAB4xIlD2WVUIrfyWlZyuSqqusrV+CdqEZVok7Vyw+ > qUmfLrIatDm2gFxBrsbHyG+8KYQhhhqIeyZapwF9xCWBFrEbeM1ltuDZF9heyefo6RdgsL414ixa > AKV9uYCv7BNi7r/wK/K3tmARUeAAQHWOCBRQWA9howMFCRzIJwMDPwE3gukAqKZhuRMhFQosFElR > n0VfH2ptVJHiYzE/EAFEAAA7 > --=_related 000F7A3F49257727_=-- > -- James Bohnsack (972) 596-6377 home/office (972) 342-5823 cell
