Re: dynamic PAV
>What am I missing to allow dynamic management of pav's? Do you have I/O Priority Management turned on? It seems basic, but without it two things happen: 1. Execution Velocity is calculated with only CPU values. 2. PAV is not dynamic. - -teD I’m an enthusiastic proselytiser of the universal panacea I believe in! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
I don't have PAV on my 9980V but I just looked at the HSP 600 we installed on Sunday. I've also got it set to 192 bases and 64 aliases in each control unit. What I see is that when the box is "at rest", only the first 64 bases have an alias assigned. I dragged out my test program that repeatedly writes and then reads 50 cylinders worth of 32K blocks. Running six concurrent copies of that shows (using TMON/MVS): BASE VOLUME: HD2F88 DEVICE: 2F88 PAV:4 START: 18:32:00.22 DURATION: 0:00:11.69 SS I/ORESP TIME IN MSEC. VOLSER ID DEVN RATE %BUSY QTIME PEND DISC CONN <---+---+---+--40> HD2F88 0 2F88 124.6 19.9 0.0 1.6 0.1 1.53.16 0 2FD4 97.5 16.5 0.0 2.1 0.2 1.5 3.77 0 2FD5 110.1 18.1 0.0 1.9 0.1 1.53.53 0 2FD6 88.6 14.9 0.0 2.4 0.2 1.5 4.04 2F88 is unitadd 88 in the CU and after a few minutes, the three aliases shown got assigned. So I think WLM is doing its thing, just not immediately. Bob Dennis Leong wrote: We recently migrated all our mainframe data to a new Hitachi storage array (9990v). In the initial setup we defined in HCD base (3390B) and alias (3390A) volumes with wlmpav=yes (for the aliases). On the storage array we have "Compatible PAV" enabled.In WLM we have Dynamic alias management set to yes. We are running z/os 1.4 and wlm in goal mode. My problem is that I cannot see any dynamic assignment of alias volumes to base volumes with high IOS queuing times. Using HDS Storage Navigator's Compatible PAV manager I see the first 64 base volumes (out of 192) with 1 alias volume in each of my control units. I have yet to see anything change over the past 4 weeks. I would have expected to see maybe a base volume (beyond the first 64) to have an alias assigned especially if the base volume has high ios queuing times (as seen in Omegamon). I can however manually assign alias volumes to base but this is not dynamic management. What am I missing to allow dynamic management of pav's? Thank you. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
Actually, 2. is incorrect. From the z/OS 1.7 WLM Planning book: "IMPORTANT: If you enable dynamic alias management, you must also enable I/O priority management. So you need to specify yes for both of these options on the panel. If I/O priority management is set to no, you will get only the efficiency part of dynamic alias management and not the goal-oriented management. This means that WLM will make alias moves that minimize overall IOS queueing, but these moves will not take service class goals into consideration." Bob Ted MacNEIL wrote: Do you have I/O Priority Management turned on? It seems basic, but without it two things happen: 1. Execution Velocity is calculated with only CPU values. 2. PAV is not dynamic. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
>So I think WLM is doing its thing, just not immediately. The PAV assignment is not immediate. I decide to (de-)allocate one, I don't do it until the next interval. I then don't look at that volume for 3 intervals. These are WLM intervals -- 10 seconds (clock) each. 2 years ago, I had a problem where that wasn't fast enough. I had a direct link to the developer (in Germany). We had come up with a solution, but after leaving IBM, I lost track, and as an external person, I have no idea what the final resolution was. - -teD I’m an enthusiastic proselytiser of the universal panacea I believe in! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
>This means that WLM will make alias moves that minimize overall IOS queueing, >but these moves will not take service class goals into consideration. TOMAY-TOE TOMAW-TOE That is a difference that makes no difference. And, a difference that makes no difference is no difference. If I'm not addressing goals: 1. Will I see it? 2. What's the point? - -teD I’m an enthusiastic proselytiser of the universal panacea I believe in! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
Ted MacNEIL wrote: This means that WLM will make alias moves that minimize overall IOS queueing, but these moves will not take service class goals into consideration. TOMAY-TOE TOMAW-TOE That is a difference that makes no difference. And, a difference that makes no difference is no difference. If I'm not addressing goals: 1. Will I see it? You might not. Your workloads might or might not. 2. What's the point? The point is that someone observing the storage array's behavior, like Dennis, should see aliases move regardless of the setting. Bob -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
>The point is that someone observing the storage array's behavior, like Dennis, should see aliases move regardless of the setting. But, what is required is something addressing goals. And, the OP was seeing nothing. - -teD I’m an enthusiastic proselytiser of the universal panacea I believe in! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
<- snip -> In the initial setup we defined in HCD base (3390B) and alias (3390A) volumes with wlmpav=yes (for the aliases). <- snip -> Do you have WLMPAV=YES for the base volumes, too? Zaromil -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
Ted MacNEIL wrote: What am I missing to allow dynamic management of pav's? Do you have I/O Priority Management turned on? It seems basic, but without it two things happen: 1. Execution Velocity is calculated with only CPU values. 2. PAV is not dynamic. Where is the switch to turn I/O Priority Management on ? -- Radoslaw Skorupka Lodz, Poland -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
>Where is the switch to turn I/O Priority Management on ? IIRC on the same screen as where you define the SDC's for CPU, SRB, MSO & IOC. - -teD I’m an enthusiastic proselytiser of the universal panacea I believe in! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
<- snip -> >Where is the switch to turn I/O Priority Management on ? IIRC on the same screen as where you define the SDC's for CPU, SRB, MSO & IOC. <- snip -> In WLM, Option 8. Service Coefficients/Options Panel "Service Coefficient/Service Definition Options": . . . Enter or change the service definition options: I/O priority management . . . . . . . . YES (Yes or No) Dynamic alias management . . . . . . . . YES (Yes or No) -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
Ted MacNEIL wrote: Where is the switch to turn I/O Priority Management on ? IIRC on the same screen as where you define the SDC's for CPU, SRB, MSO & IOC. Silly me. I was looking for it on HMC... Thank you both Ted and Zaromil -- Radoslaw Skorupka Lodz, Poland -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
Hi Dennis, I know for us Dynamic PAV just did not work unless we had both "I/O priority management" & "Dynamic alias management" set to YES in WLM. Service Coefficient/Service Definition Options Command ===> __ Enter or change the Service Coefficients: CPU . . . . . . . . . . . . . 1.0 (0.0-99.9) IOC . . . . . . . . . . . . . 0.1 (0.0-99.9) MSO . . . . . . . . . . . . . 0. (0.-99.) SRB . . . . . . . . . . . . . 1.0 (0.0-99.9) Enter or change the service definition options: I/O priority management . . . . . . . . YES (Yes or No) Dynamic alias management . . . . . . . . YES (Yes or No) Best Regards, Sam Knutson, GEICO Performance and Availability Management mailto:[EMAIL PROTECTED] (office) 301.986.3574 "Think big, act bold, start simple, grow fast..." -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Dennis Leong Sent: Tuesday, April 04, 2006 5:20 PM To: IBM-MAIN@BAMA.UA.EDU Subject: dynamic PAV We recently migrated all our mainframe data to a new Hitachi storage array (9990v). In the initial setup we defined in HCD base (3390B) and alias (3390A) volumes with wlmpav=yes (for the aliases). On the storage array we have "Compatible PAV" enabled.In WLM we have Dynamic alias management set to yes. We are running z/os 1.4 and wlm in goal mode. My problem is that I cannot see any dynamic assignment of alias volumes to base volumes with high IOS queuing times. Using HDS Storage Navigator's Compatible PAV manager I see the first 64 base volumes (out of 192) with 1 alias volume in each of my control units. I have yet to see anything change over the past 4 weeks. I would have expected to see maybe a base volume (beyond the first 64) to have an alias assigned especially if the base volume has high ios queuing times (as seen in Omegamon). I can however manually assign alias volumes to base but this is not dynamic management. What am I missing to allow dynamic management of pav's? Thank you. - enD sin This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
We have the I/O Priority Management set to Yes. I believe I've found the answer. In reviewing our device definitions in HCD, I noticed ONLY the aliases have wlmpav set to yes. The base volumes were set to NO. Thanks. "Bob Rutledge" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Ted MacNEIL wrote: >>>This means that WLM will make alias moves that minimize overall IOS >>>queueing, but these moves will not take service class goals into >>>consideration. >> >> >> TOMAY-TOE >> TOMAW-TOE >> >> That is a difference that makes no difference. >> And, a difference that makes no difference is no difference. >> >> If I'm not addressing goals: >> 1. Will I see it? > > You might not. Your workloads might or might not. > >> 2. What's the point? > > The point is that someone observing the storage array's behavior, like > Dennis, should see aliases move regardless of the setting. > > Bob > > -- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: dynamic PAV
>ONLY the aliases have wlmpav set to yes. The base volumes were set to NO. OOPS! Of course, the fact that IBM always insists that you specify options in more than one place, and if you have a mix up, not only does it not tell you, rather it behaves in the worst possible manner, would have nothing to do with this, would it? - -teD O-KAY! BLUE! JAYS! Let's PLAY! BALL! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
. I have not been able to find any statement about whether WLM will put any limit on the number of aliases that can be assigned to a particular device when using Dynamic PAVs. Does anyone on the list know of a limit? Can anyone point me to a manual that would document whether this can occur or not? . Tom, no limits on Alias associated to a Base address by WLM. If your DASD IOSQ time is high, WLM can add Aliases to Base address until IOSQ time goes down. Sometimes WLM limits the number of Aliases if it determines that adding Aliases could interfere with other response times components, like DISCONNECT times or so on. In this case WLM has an arbitrary limit. Hope this helps. _ Paolo Cacciari Business Continuity and Resiliency Services, IBM Global Services - South Region, EMEA Via Darwin 85, 20019 Settimo Milanese(MI) – Italy - MISET001 "The goal is to be prepared for a disaster not to continually plan for a successful test" * [EMAIL PROTECTED] ( + 39 051 41.36799 Mobile: + 39 335 6287584 7 + 39 02 596.23288 Fax BO: + 39 051 406052 -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
In a message dated 9/7/2007 7:59:47 A.M. Central Daylight Time, [EMAIL PROTECTED] writes: >I have not been able to find any statement about whether WLM will put any limit on the number of aliases that can be assigned to a particular device when using Dynamic PAVs. Does anyone on the list know of a limit? Can anyone point me to a manual that would document whether this can occur or not? I don't know what WLM uses as a limit, if any, but the I/O hardware has a limit of eight simultaneously active I/O requests to any one given device. Even if you have 100 aliases, there can still only be eight I/Os involving that one device occurring at the same time. These eight can come from eight different LPARs or all from one LPAR. This hardware limit of eight is true whether the PAVs are dynamic or static. I can't quickly find a document with the number eight in it, but it's in patent applications that I have studied. Bill Fairchild Plainfield, IL ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
I would look in the storage subsystem documentation. Regards, Jihad K. Kawkabani Voice: 440.395.0740 Network: 575.0740 Cell: 440.465.2969 Tom Moulder <[EMAIL PROTECTED] M.NET> To Sent by: IBM IBM-MAIN@BAMA.UA.EDU Mainframe cc Discussion List <[EMAIL PROTECTED] Subject .EDU> Dynamic PAV Device Limit? 09/07/2007 08:59 AM Please respond to IBM Mainframe Discussion List <[EMAIL PROTECTED] .EDU> I have not been able to find any statement about whether WLM will put any limit on the number of aliases that can be assigned to a particular device when using Dynamic PAVs. Does anyone on the list know of a limit? Can anyone point me to a manual that would document whether this can occur or not? Tom Moulder -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
Bill, This is not quite right. FICON is restricted by the either the number of OE supported by the channel, or the OE supported by the Storage port. On a z9 there can be 64 OE on every channel on an LCU - with eight channels that's 512 IO that can be transferring data or disconnected and waiting for a cache miss, TrueCopy RIO or such like at the same time. AFAIK there is no MVS restriction on the number of alias assigned to a device. You can have one base address with all 255 alias assigned if that is something useful. Datasets that are good candidate for FlashAccess would probably benefit for this sort of unique setup. High activity volumes with a good cache hit rate on Wide Stripe PG would also benefit. There were some restriction on the number of alias in EMC and HDS a few generations ago, but not in current models. Note that ESCON also did not have a restriction of one IO per channel. There could only be one data transfer per ESCON channel, but when an IO disconnected another IO could jump straight in and use the channel. There could be any number of IO in a Disconnect state, but only one IO per channel connected. Ron > -Original Message- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of (IBM Mainframe Discussion List) > Sent: Friday, September 07, 2007 6:40 AM > To: IBM-MAIN@BAMA.UA.EDU > Subject: Re: [IBM-MAIN] Dynamic PAV Device Limit? > > > > In a message dated 9/7/2007 7:59:47 A.M. Central Daylight Time, > [EMAIL PROTECTED] writes: > >I have not been able to find any statement about whether WLM will put > any limit on the number of aliases that can be assigned to a > particular device when using Dynamic PAVs. Does anyone on the list > know of a limit? Can anyone point me to a manual that would document > whether this can occur or not? > > I don't know what WLM uses as a limit, if any, but the I/O hardware has > a > limit of eight simultaneously active I/O > requests to any one given device. Even if you have 100 aliases, there > can > still only be eight I/Os involving that one > device occurring at the same time. These eight can come from eight > different LPARs or all from one LPAR. This hardware > limit of eight is true whether the PAVs are dynamic or static. I > can't > quickly find a document with the number eight in it, > but it's in patent applications that I have studied. > > Bill Fairchild > Plainfield, IL > > > > > > ** Get a sneak peek of the all-new > AOL at > http://discover.aol.com/memed/aolcom30tour > > -- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
On our IBM SHARKS F2105's and 8100's; we have 48 PAV's defined to each LCU. I have seen as many as 47 PAVs defined to 1 logical device. Water is put where ever the FIRE IS with Dynamic PAV's. The restriction is the number you have GEN'ed to the LCU. I do not think other DASD Vendors do this. I know at one point in time EMC has a maximum of 8 PAV's per logical device and do not know if that number has been increased. For example In your I/O GEN Real device are gen'ed as 3390B for bases PAV devices are gen'ed as 3390A for Aliases IODEVICE ADDRESS=(4000,208),CUNUMBR=(AF40),STADET=Y,UNIT=3390B IODEVICE ADDRESS=(40D0,048),CUNUMBR=(AF40),STADET=Y,UNIT=3390A Total 256 devices per LCU. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
In a message dated 9/7/2007 11:47:40 A.M. Central Daylight Time, [EMAIL PROTECTED] writes: >This is not quite right. FICON is restricted by the either the number of OE supported by the channel, or the OE supported by the Storage port. On a z9 there can be 64 OE on every channel on an LCU - with eight channels that's 512 IO that can be transferring data or disconnected and waiting for a cache miss, TrueCopy RIO or such like at the same time. I confess to ignorance of FICON details and of the acronym OE. >AFAIK there is no MVS restriction on the number of alias assigned to a device. You can have one base address with all 255 alias assigned if that is something useful. Datasets that are good candidate for FlashAccess would probably benefit for this sort of unique setup. High activity volumes with a good cache hit rate on Wide Stripe PG would also benefit. There were some restriction on the number of alias in EMC and HDS a few generations ago, but not in current models. IOS uses a PAV alias UCB to find the base UCB that is associated with that alias device number. This base UCB has in it a matrix of up to eight CHPIDs that can be used for an I/O from that LPAR to that device. There is only room in the UCB for eight CHPIDs. I used to think that the maximum number of I/Os that can be started on any one LPAR to one particular device was eight, and that was because I assumed the Channel Subsystem would not accept more than eight. I forgot about the multiplexing of multiple I/Os down one channel. After reading your post and rereading the PoOps section on the I/O Start Function, it appears that if the Channel Subsystem finds all eight (maximum possible paths to a device) channels busy (connected), then that I/O is queued in the CS; i.e., it remains Start Function pending. The CS must store this request in a queue somewhere in its HSA control blocks, and later the CS will start the 9th through the n-th I/O to the same device down whichever channel is next to indicate that it is disconnected. No matter how many "quasi-simultaneous" I/Os that the CS has started to the device, however, at any one instant no more than eight of them can possibly be connected to a channel path and actively transferring data. >Note that ESCON also did not have a restriction of one IO per channel. There could only be one data transfer per ESCON channel, but when an IO disconnected another IO could jump straight in and use the channel. There could be any number of IO in a Disconnect state, but only one IO per channel connected. The disconnect-reconnect capability has been present since the early 1970s with Block Multiplexor Channels. Whenever a control unit sees a command in the channel program that could result in a significant amount of time before that command can finish (such as a seek), the control unit disconnects that I/O operation from the channel to which is was connected. Then that channel is available to do I/O to or from any device that is accessible through that channel. I used to think that only an I/O to a different device would steal away the channel at this point. But with the advent of PAV it now seems that a different I/O to the same device could connect to the channel. Or maybe that possibility has been in the microcode since even before PAV. The patent applications to which I referred in my earlier post were those of EMC's initial support of 2105 PAV compatibility in late 2000. There is a limit of eight per device that was architected into that level of microcode. Evidently they have increased the limit to some new, much larger value. Bill Fairchild Plainfield, IL ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
>I have not been able to find any statement about whether WLM will put any >limit on the number of aliases that can be assigned to a particular device >when using Dynamic PAVs. IIRC, it's 256, but I have seen other vendors limit in the hardware (EMC). The highest I have ever seen is 50. And, that was solving a problem we didn't know we had. An IMS application was writing debugging information to SYSOUT (yes, I know). Due to the number of MPP's, one SPOOL volume was getting pounded. But, in general, I think the law of diminishing returns kicks in at around 6-8. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
Bill, > > I confess to ignorance of FICON details and of the acronym OE. > OE is short for Open Exchanges. This refers to the number of Initiator => Target relationships supported by the Host Channel and the Storage Port. If volume has 4xFICON channels and 256 Alias then technically there is no reason why there cannot be 256 IO outstanding to that volume. > > IOS uses a PAV alias UCB to find the base UCB that is associated with > that > alias device number. > This base UCB has in it a matrix of up to eight CHPIDs that can be used > for > an I/O from that LPAR to that device. > There is only room in the UCB for eight CHPIDs. I used to think that > the > maximum number of I/Os that can be started > on any one LPAR to one particular device was eight, and that was > because I > assumed the Channel > Subsystem would not accept more than eight. I forgot about the > multiplexing > of multiple I/Os down > one channel. After reading your post and rereading the PoOps section > on the > I/O Start Function, it appears that > if the Channel Subsystem finds all eight (maximum possible paths to a > device) channels busy (connected), then > that I/O is queued in the CS; i.e., it remains Start Function pending. > The > CS must store this request in a queue > somewhere in its HSA control blocks, and later the CS will start the > 9th > through the n-th I/O to the same device > down whichever channel is next to indicate that it is disconnected. > No > matter how many "quasi-simultaneous" I/Os > that the CS has started to the device, however, at any one instant no > more > than eight of them can possibly be connected > to a channel path and actively transferring data. True, but once you are in IOS you are already past the UCB. That's why it is called IOS Queue :-) With ESCON there can up to eight channels on an LCU transferring data, and an even greater number of IO Disconnected while a volume's disk is seeking, queued for sibling pend, waiting for remote copy IO, waiting for dirty cache delays, delayed for XRC sidefile full, etc. > > The disconnect-reconnect capability has been present since the early > 1970s > with Block Multiplexor > Channels. Whenever a control unit sees a command in the channel > program > that could result in a > significant amount of time before that command can finish (such as a > seek), > the control unit disconnects > that I/O operation from the channel to which is was connected. Then > that > channel is available to do I/O > to or from any device that is accessible through that channel. I used > to > think that only an I/O to a > different device would steal away the channel at this point. But with > the > advent of PAV it now seems > that a different I/O to the same device could connect to the channel. > Or > maybe that possibility has been in the > microcode since even before PAV. > And of none of the preceeding discussion (mine and yours) applies to FICON. FICON does not really have a connect and disconnect state. It is more like transferring and not transferring frames for a volume. There is no DPR - everything happens on the same channel. Think of it like a PABX that supports 64 phone calls. When 64 lines are in use you have to wait. It happens rarely for good cache IO, but for some cache unfriendly workloads (CA-IDMS and IMS Fastpath spring to mind) you can quickly use up the OE and watch IO stall waiting for cache misses to complete. > > The patent applications to which I referred in my earlier post were > those of > EMC's initial support of > 2105 PAV compatibility in late 2000. There is a limit of eight per > device > that was architected into that level of > microcode. Evidently they have increased the limit to some new, much > larger > value. Some vendors wrote their own code to talk to PAV on MVS, and some paid IBM for the API and still had limits initially. The limits on the storage were not PAV limits in MVS. Note that there are other resource restrictions that can affect FICON throughput. I suggest browsing Pat Artis' website for some quality education on FICON. > > Bill Fairchild > Plainfield, IL > > > > > -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
Ted > > But, in general, I think the law of diminishing returns kicks in at > around 6-8. > Maybe true when PG are only using 4-8 spindles, but with wide striping and large volumes a poor cache hit workloads would get a lot of benefit from 32 spindles concurrently handling IO for a volume. Ron -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
In a message dated 9/7/2007 10:03:18 P.M. Central Daylight Time, [EMAIL PROTECTED] writes: >I suggest browsing Pat Artis' website for some quality education on FICON. I am doing that now and browsing the general Internet, too. I have learned a lot over the years from Pat Artis. Based on everything I have read lately, I now believe it is possible to start 256 I/O requests from one LPAR to the same device before the first one ends if that device is in an ESS LCU with four FICON channels between that LCU and the LPAR that does the I/Os, if that LPAR has the device defined as a PAV base device with 255 alias devices in the same LCU, and if all four FICON channels are in the base device's UCB channel path matrix. These I/Os will appear to be simultaneous, but at any given instant, no more than 64 of the 256 will be actively transferring data to or from the LCU. The other 192 will be disconnected for various reasons. This is a theoretical maximum and not necessarily a practical limit. If eight ESCON channels are the link between the device and the ESS LCU, then the number of simultaneously startable I/Os to the device will be more than eight but smaller than 256. Is all of this correct? I have been away from the bleeding edge too long. :-( Bill Fairchild Plainfield, IL ** See what's new at http://www.aol.com -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
Bill > > Based on everything I have read lately, I now believe it is possible to > start 256 I/O requests from one LPAR to the > same device before the first one ends if that device is in an ESS LCU > with > four FICON channels between that > LCU and the LPAR that does the I/Os, if that LPAR has the device > defined as > a PAV base device with 255 alias > devices in the same LCU, and if all four FICON channels are in the > base > device's UCB channel path matrix. That's only if you are connected to a z9. The z990, z900 and G6 have less OE per channel so you need 8 channels to get 256 IO. There can be no other IO to any other LCU daisy chained on the same channel(s). The OE supported by the storage port must also not be exhausted due to fan-in of multiple channels. In a simple model of 4xchannels dedicated to one LCU with one base and 255 alias you are correct. > These I/Os will appear to be simultaneous, but at any given instant, > no more > than 64 of the 256 will be actively > transferring data to or from the LCU. The other 192 will be > disconnected > for various reasons. Not true. There is no disconnect on FICON. The channel is moving frames or not. The number of OE with data or command in a frame on the channel will depend on how the particular server and storage models handle interleaving. This is a theoretical > maximum and not necessarily a practical limit. If eight ESCON > channels are > the link between the device and the > ESS LCU, then the number of simultaneously startable I/Os to the device > will > be more than eight but smaller than 256. In tests with zero cache hits I've seen channels with average 47 OE - an average meaning there are times when there were larger and smaller numbers. That's with 1024 spindles and 64x4Gb channels. > > Is all of this correct? > > I have been away from the bleeding edge too long. :-( I think the discussion may be accidentally creating confusion about OE and channel limitations at a single device level. The number of OE on a channel is the sum of all IO on the channel no matter how many volumes and LCU are sharing it. Ron -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV Device Limit?
In a message dated 9/9/2007 8:34:21 P.M. Central Daylight Time, [EMAIL PROTECTED] writes: >I think the discussion may be accidentally creating confusion about OE and channel limitations at a single device level. The number of OE on a channel is the sum of all IO on the channel no matter how many volumes and LCU are sharing it. I understand this point. I was using only one device in my discussion as the extreme case, where extreme means from the point of view of how it used to work, namely only one I/O at a time to any given device. Bill Fairchild Plainfield, IL ** See what's new at http://www.aol.com -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
"Dave Butts" wrote in message news:... > Has anyone experienced all dynamic PAV activity just stopping? > > RMF reports are showing me that there have been "zero" changes to our alias > assignments for the past couple weeks. Lickily our PAVs are currently spread > out enough over the production UCBs that we have not had terrible > performance due to poor dasd response. > > Funny thing is - the dynamic PAV assignment activity ceased on a Saturday > night after IBM was in to apply periodic MCL upgrades to the z9. > > We have an incident open with IBM but wanted to see if anyone else has > experoenced this??? > > Thanks, > Dave > When was your MCL upgrade? Our last upgrade was first half of April and I still see PAVs moving. Kees. ** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ** -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
>Has anyone experienced all dynamic PAV activity just stopping? Check both your IODF & WLM policy. Both have to have PAV turned on. If one doesn't, then it won't be active. We implemented dynamic, aeons ago, in the following manner: 1. Assign one alias to each volume (we had enough at the time). 2. Turn dynamic PAVs on in the IODF. 3. Turn on I/O Priority Management under WLM (we had to wait until disconnect was no longer part of velocity), and adjust velocities accordingly. 4. Finally, turn on dynamic in the WLM. Then, dynamic PAVs were active. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
The MCLs were applied on May 2. On Thu, 4 Jun 2009 16:47:59 +0200, Vernooy, C.P. - SPLXM wrote: >> > >When was your MCL upgrade? >Our last upgrade was first half of April and I still see PAVs moving. > >Kees. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
In a message dated 6/4/2009 10:02:53 A.M. Central Daylight Time, kees.vern...@klm.com writes: When was your MCL upgrade? Our last upgrade was first half of April and I still see PAVs moving. >> Parts is parts. Guess we need to know more info. z9---z/CHPIDs---z/Controller MCL Type and number of CHPIDs. z/Controller and service level. CE should have any prereq's or mismatches in HONE for MCL. **Limited Time Offers: Save big on popular laptops at Dell (http://pr.atwola.com/promoclk/100126575x1221354145x1201369495/aol?redir=http:%2F %2Fad.doubleclick.net%2Fclk%3B215221161%3B37268813%3By) -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
On Thu, 4 Jun 2009 09:16:52 -0500, Dave Butts wrote: >Has anyone experienced all dynamic PAV activity just stopping? > >RMF reports are showing me that there have been "zero" changes to our alias >assignments for the past couple weeks. Lickily our PAVs are currently spread >out enough over the production UCBs that we have not had terrible >performance due to poor dasd response. > >Funny thing is - the dynamic PAV assignment activity ceased on a Saturday >night after IBM was in to apply periodic MCL upgrades to the z9. > >We have an incident open with IBM but wanted to see if anyone else has >experoenced this??? > You still have PAV's though - just not changing? If this is a z/OS bug / issue as opposed to bad MCL (which I don't know why a z9 MCL would affect PAVs), I have seen some other WLM bugs resolved by re-activating the WLM policy. Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:mark.zel...@zurichna.com z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
LS, More important is your IOSQ time increasing ? Are the number of PAV adresses insufficient ? 2009/6/4 Dave Butts > Has anyone experienced all dynamic PAV activity just stopping? > > RMF reports are showing me that there have been "zero" changes to our alias > assignments for the past couple weeks. Lickily our PAVs are currently > spread > out enough over the production UCBs that we have not had terrible > performance due to poor dasd response. > > Funny thing is - the dynamic PAV assignment activity ceased on a Saturday > night after IBM was in to apply periodic MCL upgrades to the z9. > > We have an incident open with IBM but wanted to see if anyone else has > experoenced this??? > > Thanks, > Dave > > -- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > -- Met vriendelijke groeten/With kind regards Dick de Groot -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
>More important is your IOSQ time increasing ? >Are the number of PAV adresses >insufficient ? The OP said he was fine, for now. But, I/O patterns do change, over the day, and over time. I still think the IODF and the WLM policy should be checked to see if it's enabled in both. It may be; it is a good idea to eliminate them as issues. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Indeed, and that may be exactly what happened: a change to the workload eliminated or reduced volume contention such that PAV redistribution is no longer needed. AFAIK, WLM will move a PAV only when it believes that doing so will help some workload that is not meeting its goals. -Original Message- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Ted MacNEIL Sent: Thursday, June 04, 2009 2:03 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Dynamic PAV assigment has stopped >More important is your IOSQ time increasing ? >Are the number of PAV adresses >insufficient ? The OP said he was fine, for now. But, I/O patterns do change, over the day, and over time. I still think the IODF and the WLM policy should be checked to see if it's enabled in both. It may be; it is a good idea to eliminate them as issues. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
>Indeed, and that may be exactly what happened: a change to the workload >eliminated or reduced volume contention such that PAV redistribution is no >longer needed. I didn't say a change to the workload. I said a change to WLM or IODF. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Ah, but you did: "But, I/O patterns do change, over the day, and over time." And I agree with that as well the rest of your excellent advise. -Original Message- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Ted MacNEIL Sent: Thursday, June 04, 2009 2:24 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Dynamic PAV assigment has stopped >Indeed, and that may be exactly what happened: a change to the workload >eliminated or reduced volume contention such that PAV redistribution is no >longer needed. I didn't say a change to the workload. I said a change to WLM or IODF. - Too busy driving to stop for gas! NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
>Ah, but you did: >>"But, I/O patterns do change, over the day, and over time." >And I agree with that as well the rest of your excellent advise. I guess I wasn't clear. I find it difficult to believe that not a single PAV was re-assigned in a month. That was the purpose of my 'pattern' statement. That's why I said eliminate the possibility of the WLM policy or the IODF changing with regard to dynamic PAV. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Yea, we checked the IODF and the WLM policy. No changes there. Last IODF change was earlier in April and everything is still set for PAV in there and in the WLM policy. I liked the idea of reactivating the policy, but I checked and we have activated new policies with minor changes a couple times in the past few weeks (after the problem appeared). Thanks, Dave On Thu, 4 Jun 2009 19:43:50 +, Ted MacNEIL wrote: >>Ah, but you did: > >>>"But, I/O patterns do change, over the day, and over time." > > >>And I agree with that as well the rest of your excellent advise. > >I guess I wasn't clear. >I find it difficult to believe that not a single PAV was re-assigned in a >month. >That was the purpose of my 'pattern' statement. > >That's why I said eliminate the possibility of the WLM policy or the IODF changing with regard to dynamic PAV. > >- >Too busy driving to stop for gas! > >-- >For IBM-MAIN subscribe / signoff / archive access instructions, >send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO >Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Do you have HyperPAV implemented? Terry Traylor charlesSCHWAB TIS Mainframe Storage Management Remedy Queue: tis-hs-mstg (602) 977-5154 -Original Message- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Dave Butts Sent: Thursday, June 04, 2009 7:17 AM To: IBM-MAIN@bama.ua.edu Subject: Dynamic PAV assigment has stopped Has anyone experienced all dynamic PAV activity just stopping? RMF reports are showing me that there have been "zero" changes to our alias assignments for the past couple weeks. Lickily our PAVs are currently spread out enough over the production UCBs that we have not had terrible performance due to poor dasd response. Funny thing is - the dynamic PAV assignment activity ceased on a Saturday night after IBM was in to apply periodic MCL upgrades to the z9. We have an incident open with IBM but wanted to see if anyone else has experoenced this??? Thanks, Dave -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Good! All I said was: "check it out"! Never said it was the issue. >Yea, we checked the IODF and the WLM policy. >No changes there. >Last IODF change was earlier in April and everything is still set for PAV in >there and in the WLM policy. - Too busy driving to stop for gas! -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
We have HyperPAV implemented on one test box. It is actually working fine. Only the WLM dynamic PAV is not working (on the rest of the dasd farm). Still working with IBM support. They are a little stumped so far, but have been able to find that the root problem is that the DBVT (Device Block Vector Table) is empty and does not have slots for PAVMB pointers for devices with an mbi greater than 3277. Still trying to figure out why... On Thu, 4 Jun 2009 13:12:19 -0700, Traylor, Terry wrote: >Do you have HyperPAV implemented? > > >Terry Traylor >charlesSCHWAB >TIS Mainframe Storage Management >Remedy Queue: tis-hs-mstg >(602) 977-5154 > -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
It was an OS problem after all, and not due to the MCLs. APAR OA29370 has been opened. We have been over the 65535 device boundry for a long time, but the bug became exposed when I deleted over 5000 addresses the week before via dynamic iogen activate. The PAV assignment code broke because of the 2 byte CMCTHMBI field. We have just been lucky for several years that the truncated value (to fit the field) resulted in a value that was higher than our highest UCB. With the recent deletion of the 5000+ devices along with the truncation, we ended up with a total number of devices being tracked that is less than our starting DASD UCB. Strange though that the propblem didn't actually start until the next weekend when we performed a power-on-reset. Still investigating that one... Dave -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
- Original Message - From: "Dave Butts" Newsgroups: bit.listserv.ibm-main Sent: Wednesday, June 10, 2009 4:07 PM Subject: Re: Dynamic PAV assigment has stopped It was an OS problem after all, and not due to the MCLs. APAR OA29370 has been opened. We have been over the 65535 device boundry for a long time, but the bug became exposed when I deleted over 5000 addresses the week before via dynamic iogen activate. The PAV assignment code broke because of the 2 byte CMCTHMBI field. We have just been lucky for several years that the truncated value (to fit the field) resulted in a value that was higher than our highest UCB. With the recent deletion of the 5000+ devices along with the truncation, we ended up with a total number of devices being tracked that is less than our starting DASD UCB. Strange though that the propblem didn't actually start until the next weekend when we performed a power-on-reset. Still investigating that one... Dave Dave, Please let us know if IBM is going to refund the PAV licenses you paid for the past few months it hasn't been working. Regards, Tom Conley -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Just curious: why a POR? -Original Message- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Dave Butts Sent: Wednesday, June 10, 2009 3:07 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Dynamic PAV assigment has stopped It was an OS problem after all, and not due to the MCLs. APAR OA29370 has been opened. We have been over the 65535 device boundry for a long time, but the bug became exposed when I deleted over 5000 addresses the week before via dynamic iogen activate. The PAV assignment code broke because of the 2 byte CMCTHMBI field. We have just been lucky for several years that the truncated value (to fit the field) resulted in a value that was higher than our highest UCB. With the recent deletion of the 5000+ devices along with the truncation, we ended up with a total number of devices being tracked that is less than our starting DASD UCB. Strange though that the propblem didn't actually start until the next weekend when we performed a power-on-reset. Still investigating that one... Dave NOTICE: This electronic mail message and any files transmitted with it are intended exclusively for the individual or entity to which it is addressed. The message, together with any attachment, may contain confidential and/or privileged information. Any unauthorized review, use, printing, saving, copying, disclosure or distribution is strictly prohibited. If you have received this message in error, please immediately advise the sender by reply email and delete all copies. -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
"Dave Butts" wrote in message news:... > It was an OS problem after all, and not due to the MCLs. > APAR OA29370 has been opened. > > We have been over the 65535 device boundry for a long time, but the bug > became exposed when I deleted over 5000 addresses the week before via > dynamic iogen activate. The PAV assignment code broke because of the 2 > byte CMCTHMBI field. We have just been lucky for several years that the > truncated value (to fit the field) resulted in a value that was higher than our > highest UCB. With the recent deletion of the 5000+ devices along with the > truncation, we ended up with a total number of devices being tracked that is > less than our starting DASD UCB. > Just out of curiosity: 65535 devices per what? IOCDS, storage device? Makes me feel working in a small shop... Kees. ** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ** -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
Per IOCDS. Many of our addresses are open systems dasd (for FDR backup purposes). Dave On Thu, 11 Jun 2009 08:53:32 +0200, Vernooy, C.P. - SPLXM wrote: >> > >Just out of curiosity: 65535 devices per what? IOCDS, storage device? >Makes me feel working in a small shop... > >Kees. >* * -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV assigment has stopped
On Wed, 10 Jun 2009 15:06:54 -0500, Dave Butts wrote: >It was an OS problem after all, and not due to the MCLs. >APAR OA29370 has been opened. > >We have been over the 65535 device boundry for a long time, but the bug >became exposed when I deleted over 5000 addresses the week before via >dynamic iogen activate. The PAV assignment code broke because of the 2 >byte CMCTHMBI field. We have just been lucky for several years that the >truncated value (to fit the field) resulted in a value that was higher than our >highest UCB. With the recent deletion of the 5000+ devices along with the >truncation, we ended up with a total number of devices being tracked that is >less than our starting DASD UCB. > >Strange though that the propblem didn't actually start until the next weekend >when we performed a power-on-reset. >Still investigating that one... > Here's another one APAR Identifier .. OA29016 Last Changed 09/06/25 UNABLE TO BIND PAV DEVICES FOLLOWING AN ACTIVATE FAILURE Symptom .. IN INCORROUT Status ... CLOSED PER Severity ... 2 Date Closed . 09/06/25 Component .. 5752SC1C3 Duplicate of Reported Release . 730 Fixed Release 999 Component Name IOS Special Notice HIPER Current Target Date ..09/08/28 Flags SCP ... FUNCTIONLOSS Platform Status Detail: APARCLOSURE - APAR is being closed. PE PTF List: PTF List: Release 730 : PTF not available yet Release 730 : Relief is available in the form of: PTF Release 740 : PTF not available yet Release 740 : Relief is available in the form of: PTF Release 750 : PTF not available yet Release 750 : Relief is available in the form of: PTF Release 760 : PTF not available yet Release 760 : Relief is available in the form of: PTF Parent APAR: Child APAR list: ERROR DESCRIPTION: Customer performed an ACTIVATE SOFT, which involved changes on the usage of base and alias devices. During dynamic configuration change processing, IOS sets indicators in the devices being changed to prevent them from being bound again during the dynamic change. However, if the activate fails and all traditional PAV devices were unbound, configuration change processing fails to reset these indicators. This prevents these devices from future binding. VERIFICATION STEPS: 1. Binds are not occurring following an ACTIVATE TEST 2. Check SYSLOG for IOS500I message to determine if TEST is used with ACTIVATE. 3. Get a dump of IOSAS very soon after failure (or if can recreate, after you recreate) 4. Run CTRACE COMP(SYSIOS) SUMM LOCAL 5. Find the date in question F 'mm/dd/' 6. F 'Dyn config change - Start' to find the start of the activate. 7. F CMV1 eyecatcher entries after start for one device in question. 8. Check the UCBXNBND Counter for that device and then find the device again checking to see if counter is non-zero. UCBXNBND bit is UCBX+6F = 80 bit. Counter is UCBOB + x'34' LOCAL FIX: PROBLEM SUMMARY: * USERS AFFECTED: Users at HBB7730 and above. * * PROBLEM DESCRIPTION: After a failed ACTIVATE, unbound* * traditional PAVs are unable to bind or * * perform I/O because the back out* * processing is incorrectly skipped for * * these devices. * * PAV PAVS D/T2105 D/T2107 D/T1750* * RECOMMENDATION: * During the course of an ACTIVATE, PAV Aliases undergo processing to prevent them from being bound while dynamic changes to the configuration are happening. If an error occurs during an ACTIVATE, this processing should be backed out so that the Aliases can be bound as before. However, if only PAV Aliases of the unbound traditional type are being changed, the back out processing does not occur as expected and attempts to bind the effected PAVs will fail. PROBLEM CONCLUSION: Error processing will be changed so that all PAV Aliases will undergo back out processing to be returned to their original state and therefore be able to be bound. -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:mark.zel...@zurichna.com z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsut
Re: Dynamic PAV - which alias will be moved
Hi Kevin, Are your spare volumes defined with WLMPAV=YES in your I/O config? Or, is it possible to disable dynamic alias management for certain volumes directly in the STK box? -- Zaromil -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV - which alias will be moved
Hello, All volumes are defined the same way, WLMPAV=YES. Furthermore, some of these spare volumes were production volumes before we started moving to model27. And at that time, they 'took part' in the dynamic PAV process. Vriendelijke Groeten / Best Regards / Med Vänliga Hälsningar Kevin Somers System Engineering Mainframe Volvo IT Belgium E-mail: [EMAIL PROTECTED] -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Zaromil Tisler Sent: woensdag 8 oktober 2008 10:03 To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Dynamic PAV - which alias will be moved Hi Kevin, Are your spare volumes defined with WLMPAV=YES in your I/O config? Or, is it possible to disable dynamic alias management for certain volumes directly in the STK box? -- Zaromil -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Dynamic PAV - which alias will be moved
Hi Kevin, WLM is indeed a complex beast. I will not pretend to be able to completely answer all of your questions here, as there are a number of variables involved, but I will attempt to provide some insight. Firstly, there are two algorithms that WLM uses to decide on the assignment of Dynamic PAV's. The first is the GOAL algorithm. This is the one we think of when WLM is trying to 'help' a workload. In order to come into play, you do not just need IOSQ time, you need a Service Class Period that is not meeting its goal due to I/O queue time and a free PAV from either an idle disk or another Service Class Period that can afford to donate. WLM will weigh the pros and cons of the move before making it. Note that this action only takes place every 30 seconds. The second is the Efficiency algorithm. In this case, WLM will survey all of the I/O activity and attempt to distribute the available PAV's to provide the best overall throughput. This algorithm runs every 60 seconds. For a detailed understanding of what WLM is thinking, you need to collect some type 99 SMF records. As you may know, they are quite lengthy and are likely turned off in your shop. Perhaps try temporarily turning them on during a period when you would expect to see movement (15 min or so should give you some reasonable insight). Finally, while this is not the forum for a sales pitch, talk to us at IntelliMagic. We can help. Best regards, John Baker -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
