Re: Sharing z/OS DASD under VM
In [EMAIL PROTECTED], on 11/04/2005 at 08:06 AM, Knutson, Sam [EMAIL PROTECTED] said: This is perfectly safe since z/VM will enforce read only access if that is the way a disk is attached you are not violating any sharing rules. FSVO safe. It will certainly protect the R/O volumes, but, as you mention, you might get incorrect results on some reads if you skip the serialization. If you are depending on out from the system being correct then you are at risk. -- 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 [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: Sharing z/OS DASD under VM
In the TMON lab we always ran new ESP releases of z/OS under z/VM just so we could have read only access to our existing DASD in the Sysplex before toleration service was available to actually bring the guests into the Sysplex. This worked well you just have to have some volumes exclusive under z/VM read/write for work data sets on the guest. It allowed us to easily import or reference data sets from our normal systems. This is perfectly safe since z/VM will enforce read only access if that is the way a disk is attached you are not violating any sharing rules. If you have problems it will be in the guest reading something dirty without serialization but that was acceptable for our test systems. 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- Oh, I'm not too sure how well z/OS will tolerate a read only disk. I remember doing it long ago with MVS 3.8j and VM/370. I'd get some strange I/O errors at times. 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: Sharing z/OS DASD under VM
Thank you to everyone for your help and advice Crispin Hugo Systems Programmer, Macro 4 http://www.macro4.com/ Macro 4 plc, The Orangery, Turners Hill Road, Worth, Crawley, RH10 4SS Direct Line: +44 (0)1293 872121 Switchboard: +44 (0) 1293 872000 Fax: +44 (0) 1293 872001 This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation, offer or acceptance of any offer. -Original Message- This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. -- 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
Sharing z/OS DASD under VM
Quick question to the experts, Is there an easy way to share a DASD between 5 or more z/OS systems under z/VM. We would like to put some files on DASD that can then be read by another other z/OS system who has access to the DASD. I don't want more than 1 machine to write to any file. Sort of read only access required. The data sets do not need to be cataloged. Crispin Hugo Systems Programmer This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. -- 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: Sharing z/OS DASD under VM
Crispin Hugo wrote: Quick question to the experts, Is there an easy way to share a DASD between 5 or more z/OS systems under z/VM. We would like to put some files on DASD that can then be read by another other z/OS system who has access to the DASD. I don't want more than 1 machine to write to any file. Sort of read only access required. The data sets do not need to be cataloged. Multiple-guest, read-only access is supported by VM. -- - | Edward E. Jaffe|| | Mgr, Research Development| [EMAIL PROTECTED]| | Phoenix Software International | Tel: (310) 338-0400 x318 | | 5200 W Century Blvd, Suite 800 | Fax: (310) 338-0801| | Los Angeles, CA 90045 | http://www.phoenixsoftware.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: Sharing z/OS DASD under VM
Thanks Ed. I am unsure about what MVS will think of Read only. I don't think it understands it. Crispin Hugo Systems Programmer, Macro 4 http://www.macro4.com/ Macro 4 plc, The Orangery, Turners Hill Road, Worth, Crawley, RH10 4SS Direct Line: +44 (0)1293 872121 Switchboard: +44 (0) 1293 872000 Fax: +44 (0) 1293 872001 This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation, offer or acceptance of any offer. -Original Message- From: Edward E. Jaffe [mailto:[EMAIL PROTECTED] Sent: 03 November 2005 20:18 To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Sharing z/OS DASD under VM Crispin Hugo wrote: Quick question to the experts, Is there an easy way to share a DASD between 5 or more z/OS systems under z/VM. We would like to put some files on DASD that can then be read by another other z/OS system who has access to the DASD. I don't want more than 1 machine to write to any file. Sort of read only access required. The data sets do not need to be cataloged. Multiple-guest, read-only access is supported by VM. -- - | Edward E. Jaffe|| | Mgr, Research Development| [EMAIL PROTECTED]| | Phoenix Software International | Tel: (310) 338-0400 x318 | | 5200 W Century Blvd, Suite 800 | Fax: (310) 338-0801| | Los Angeles, CA 90045 | http://www.phoenixsoftware.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 This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. -- 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: Sharing z/OS DASD under VM
-Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Crispin Hugo Sent: Thursday, November 03, 2005 2:14 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Sharing z/OS DASD under VM Quick question to the experts, Is there an easy way to share a DASD between 5 or more z/OS systems under z/VM. We would like to put some files on DASD that can then be read by another other z/OS system who has access to the DASD. I don't want more than 1 machine to write to any file. Sort of read only access required. The data sets do not need to be cataloged. Crispin Hugo Systems Programmer Yes, I've done it in the past. The main thing, to me, is to use an MDISK statement (not a DEDICATE) which defines the entire volume. There are two basic ways to do this. MDISK vdev 3390 0 END volser MWV or MDISK vdev DEVNO rdev MWV vdev is the virtual address that you want the device to be addressed at by the guest. rdev is the real address. The MWV says: Multiple Write Virtual-device-reserve-release. This emulates normal device reserve-release so that you just gen the device as SHARED in z/OS and it works. On non-owning guests, you would do: LINK owning-guest vdev1 vdev2 MWV Where vdev1 is this guest's virtual device address and vdev2 is the owner's virtual device address (they can be the same or different). You could also do a READ-ONLY link with LINK owning-guest vdev1 vdev2 RRV Ref: http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/HCSG0B01/3.2. 30 Cataloged or uncatalogued is irrelevant to this facility. Note that the owning-guest does not need to be logged on or anything for this to work. We do this at D.R. where we run under z/VM. Oh, I'm not too sure how well z/OS will tolerate a read only disk. I remember doing it long ago with MVS 3.8j and VM/370. I'd get some strange I/O errors at times. -- John McKown Senior Systems Programmer UICI Insurance Center Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its' content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited. -- 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: Sharing z/OS DASD under VM
Oh, I'm not too sure how well z/OS will tolerate a read only disk. I remember doing it long ago with MVS 3.8j and VM/370. I'd get some strange I/O errors at times. Even when you open a dataset for just INPUT, OPEN may want to rewrite the F1 DSCB to update the last reference date if is not already set to today. This will fail if the disk is read/only. However, IBMLINK finds some APARS from 1982 (OZ56722, OZ60158, OZ63205) which modified O/C/E to be tolerant of a write inhibit error on the DSCB if opening the dataset for INPUT. The APARs mention VM but us oldtimers remember that 3330s and 3350s had a switch to put the disk into read/only mode. Unless IBM has regressed those changes in the last 20 years, VM volumes in R/O mode should work. -- Bruce A. Black Senior Software Developer for FDR Innovation Data Processing 973-890-7300 personal: [EMAIL PROTECTED] sales info: [EMAIL PROTECTED] tech support: [EMAIL PROTECTED] web: www.innovationdp.fdr.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: Sharing z/OS DASD under VM
Thanks Bruce, worth a try Crispin Hugo Systems Programmer, Macro 4 http://www.macro4.com/ Macro 4 plc, The Orangery, Turners Hill Road, Worth, Crawley, RH10 4SS Direct Line: +44 (0)1293 872121 Switchboard: +44 (0) 1293 872000 Fax: +44 (0) 1293 872001 This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation, offer or acceptance of any offer. -Original Message- From: Bruce Black [mailto:[EMAIL PROTECTED] Sent: 03 November 2005 21:05 To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Sharing z/OS DASD under VM Oh, I'm not too sure how well z/OS will tolerate a read only disk. I remember doing it long ago with MVS 3.8j and VM/370. I'd get some strange I/O errors at times. Even when you open a dataset for just INPUT, OPEN may want to rewrite the F1 DSCB to update the last reference date if is not already set to today. This will fail if the disk is read/only. However, IBMLINK finds some APARS from 1982 (OZ56722, OZ60158, OZ63205) which modified O/C/E to be tolerant of a write inhibit error on the DSCB if opening the dataset for INPUT. The APARs mention VM but us oldtimers remember that 3330s and 3350s had a switch to put the disk into read/only mode. Unless IBM has regressed those changes in the last 20 years, VM volumes in R/O mode should work. -- Bruce A. Black Senior Software Developer for FDR Innovation Data Processing 973-890-7300 personal: [EMAIL PROTECTED] sales info: [EMAIL PROTECTED] tech support: [EMAIL PROTECTED] web: www.innovationdp.fdr.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 This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. -- 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: Sharing z/OS DASD under VM
Crispin Hugo wrote: Thanks Ed. I am unsure about what MVS will think of Read only. I don't think it understands it. We do it all the time. You get an IOS message (cmd reject) written to the console when z/OS attempts to write to a read-only device. -- - | Edward E. Jaffe|| | Mgr, Research Development| [EMAIL PROTECTED]| | Phoenix Software International | Tel: (310) 338-0400 x318 | | 5200 W Century Blvd, Suite 800 | Fax: (310) 338-0801| | Los Angeles, CA 90045 | http://www.phoenixsoftware.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: Sharing z/OS DASD under VM
Thanks Ed, that would not be a problem Crispin Hugo Systems Programmer, Macro 4 http://www.macro4.com/ Macro 4 plc, The Orangery, Turners Hill Road, Worth, Crawley, RH10 4SS Direct Line: +44 (0)1293 872121 Switchboard: +44 (0) 1293 872000 Fax: +44 (0) 1293 872001 This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation, offer or acceptance of any offer. -Original Message- From: Edward E. Jaffe [mailto:[EMAIL PROTECTED] Sent: 03 November 2005 21:23 To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Sharing z/OS DASD under VM Crispin Hugo wrote: Thanks Ed. I am unsure about what MVS will think of Read only. I don't think it understands it. We do it all the time. You get an IOS message (cmd reject) written to the console when z/OS attempts to write to a read-only device. -- - | Edward E. Jaffe|| | Mgr, Research Development| [EMAIL PROTECTED]| | Phoenix Software International | Tel: (310) 338-0400 x318 | | 5200 W Century Blvd, Suite 800 | Fax: (310) 338-0801| | Los Angeles, CA 90045 | http://www.phoenixsoftware.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 This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. This email has been scanned for all known viruses by the MessageLabs Email Security Service and the Macro 4 plc internal virus protection system. -- 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: Sharing z/OS DASD under VM
I got a note from a friend who works for a disk vendor that confirms that when they have disks in r/o mode, MVS open for INPUT works just fine, no DSCB update errors. -- Bruce A. Black Senior Software Developer for FDR Innovation Data Processing 973-890-7300 personal: [EMAIL PROTECTED] sales info: [EMAIL PROTECTED] tech support: [EMAIL PROTECTED] web: www.innovationdp.fdr.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: Sharing z/OS DASD under VM
On Nov 3, 2005, at 2:32 PM, Crispin Hugo wrote: Thanks Ed. I am unsure about what MVS will think of Read only. I don't think it understands it. The dataset may be read only but what about the VTOC (date last used) ? Ed -- 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
