> -----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
