Re: SYSIEFSD.Q4 resource
SYSIEFSD Q4 (and its cousins CHNGDEV and VARYDEVS) are used by MVS ALLOCATION to serialize state changes made to devices during allocation processing. Unless things have changed since I was there, these ENQs are never propagated (SCOPE=SYSTEM). I don't know what is meant by IOS involvement, but ALLOCATION will invoke various services that definitely cause I/O while holding these resources. Steve Jones did a very nice job describing the problems associated with these resources in '06 at Share in Seattle. Have a look at: http://proceedings.share.org/client_files/SHARE_in_Seattle/S2848SJ112434.pdf Scott Fagen Chief Architect - Mainframe CA Technologies -- 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: SYSIEFSD.Q4 resource
In 9045684941182920.wa.victorworkcnyahoo.com...@bama.ua.edu, on 12/01/2011 at 08:51 PM, Victor Zhang victor_wor...@yahoo.com.cn said: The process of getting SYSIEFSD.Q4 has nothing to do with hardware, it is purely an OS control block manipulation? Yes. Like any other ENQ resource, if you configure GRS to propogate the ENQ then ENQ will use a CTCA or CF, but that's a separate issue. -- Shmuel (Seymour J.) Metz, SysProg and JOAT ISO position; see http://patriot.net/~shmuel/resume/brief.html We don't care. We don't have to care, we're Congress. (S877: The Shut up and Eat Your spam act of 2003) -- 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
SYSIEFSD.Q4 resource
Hello experts, One question regarding to SYSIEFSD.Q4 resource: What is it used? Where can I find information about it? If a job tried to allocate a tape drive, will iOS tries to communicate with tape drive first before it can get share access of SYSIEFSD.Q4? Or allocation only related with software control block manipualtion? Sorry for asking this. Just trying to know if get SYSIEFSD.Q4 resource involve hardware communication or not? Thanks Victor -- 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: SYSIEFSD.Q4 resource
Hello experts, One question regarding to SYSIEFSD.Q4 resource: What is it used? Where can I find information about it? If a job tried to allocate a tape drive, will iOS tries to communicate with tape drive first before it can get share access of SYSIEFSD.Q4? Or allocation only related with software control block manipualtion? Have you tried to search this on the internet? Have you looked in the PLANNING FOR GRS type manuals on IBMs website? A quick search turned up the following short answer snip Mon, 02 Oct 2006 10:54:27 -0700 This has been a problem of varying severity ever since OS/360 Release 10 back in 1967 or so. I think Q4 is/was the UCB resource - but SYSIEFSD Q4 and Q5 were locked during OS/360 allocation - the most egregious form being an AVR tape mount, which blocked all other initiator processing. (also from an IBM Apar OA12454 Nov 7 2006) The VARY OFFLINE command is changed to wait for 5 seconds for the SYSIEFSD.Q4 resource to be obtained. If it is not obtained within 5 seconds, the request for the resource is cancelled to allow stalled Allocations to proceed. New message MSGCNZ0010A is issued to indicate that the command is delayed. VARY will then request SYSIEFSD.Q4 again and repeat the wait/cancel/reobtain processing until the resource is finally obtained. The IEEVARYD offline service is also changed in the same way as the VARY OFFLINE command. However, for IEEVARYD callers that cannot tolerate a delayed return from the service, a new flag, VDEV_DO_NOT_WAIT_FOR_ENQ, can be set so that the IEEVARYD service returns to the caller if the SYSIEFSD.Q4 resource cannot be obtained within 5 seconds. In this case, register 15 will contain a new return code, RC0C, on return from the IEEVARYD service. The caller of the service can choose to retry the IEEVARYD request if appropriate. end snip Lizette -- 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: SYSIEFSD.Q4 resource
The lock on Q4 was bad for a tape mount, but in those old days, we had lots of mountable 3330 volumes, and those mounts, which always took minutes, since the tape librarian had to dismount the existing volume after it spun down, then go find the disk (and visit with Sally on the way) and then mount the new volume. And during this locked time, not only were no jobs initiated, no TSO user could issue a SAVE or EDIT a new dataset. We ran into this 360 issue when we first began to use TSO in late 72 or early 73, and fortunately, made the connection to the disk mount, and eliminated the lock by requiring all users of mountable 3330 packs to insert an IEFBR14 step to premount the volume with DISP=SHR which eliminated the lock. And this was one of the items in my first SHARE presentation in 1974. Barry Merrill -Original Message- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On Behalf Of Lizette Koehler Sent: Thursday, December 01, 2011 7:05 AM To: IBM-MAIN@bama.ua.edu Subject: Re: SYSIEFSD.Q4 resource Hello experts, One question regarding to SYSIEFSD.Q4 resource: What is it used? Where can I find information about it? If a job tried to allocate a tape drive, will iOS tries to communicate with tape drive first before it can get share access of SYSIEFSD.Q4? Or allocation only related with software control block manipualtion? Have you tried to search this on the internet? Have you looked in the PLANNING FOR GRS type manuals on IBMs website? A quick search turned up the following short answer snip Mon, 02 Oct 2006 10:54:27 -0700 This has been a problem of varying severity ever since OS/360 Release 10 back in 1967 or so. I think Q4 is/was the UCB resource - but SYSIEFSD Q4 and Q5 were locked during OS/360 allocation - the most egregious form being an AVR tape mount, which blocked all other initiator processing. (also from an IBM Apar OA12454 Nov 7 2006) The VARY OFFLINE command is changed to wait for 5 seconds for the SYSIEFSD.Q4 resource to be obtained. If it is not obtained within 5 seconds, the request for the resource is cancelled to allow stalled Allocations to proceed. New message MSGCNZ0010A is issued to indicate that the command is delayed. VARY will then request SYSIEFSD.Q4 again and repeat the wait/cancel/reobtain processing until the resource is finally obtained. The IEEVARYD offline service is also changed in the same way as the VARY OFFLINE command. However, for IEEVARYD callers that cannot tolerate a delayed return from the service, a new flag, VDEV_DO_NOT_WAIT_FOR_ENQ, can be set so that the IEEVARYD service returns to the caller if the SYSIEFSD.Q4 resource cannot be obtained within 5 seconds. In this case, register 15 will contain a new return code, RC0C, on return from the IEEVARYD service. The caller of the service can choose to retry the IEEVARYD request if appropriate. end snip Lizette -- 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: SYSIEFSD.Q4 resource
Barry, AND to add to this was the infamous 3850 that killed Q4. Ed -- 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: SYSIEFSD.Q4 resource
In 8731877265338657.wa.victorworkcnyahoo.com...@bama.ua.edu, on 12/01/2011 at 06:42 AM, Victor Zhang victor_wor...@yahoo.com.cn said: What is it used? Allocation. Where can I find information about it? The job management logic manuals that IBM no longer provides to customers. If a job tried to allocate a tape drive, will iOS tries to communicate with tape drive first before it can get share access of SYSIEFSD.Q4? IOS has nothing to do with the SYSIEFSD resources. -- Shmuel (Seymour J.) Metz, SysProg and JOAT ISO position; see http://patriot.net/~shmuel/resume/brief.html We don't care. We don't have to care, we're Congress. (S877: The Shut up and Eat Your spam act of 2003) -- 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: SYSIEFSD.Q4 resource
Hello experts, So based on your replies, can I get a conclusion like this: The process of getting SYSIEFSD.Q4 has nothing to do with hardware, it is purely an OS control block manipulation? Regards Victor -- 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
