Re: VM directory entry for shared DASD

[Edward M. Martin]

Title: VM directory entry for shared DASD

Hello David,         It is my understanding the to share DASD across systems under z/VM, you need to have the MWV on the MDISK and the VSE lock file to ensure integrity.   The MWV will invoke the CP RESERVE/RELEASE that is required by the VSE Lock file.         Now my question I would like to add,  I have two separate CPU’s using the same DASD (some EMC system to be exact). I have two z/VM systems that have access to the same VSE systems.   Will the lock file on VSE protect the files?         Both have MWV for the Mdisk and MW for the links.  If CPU A starts TEST and CPU B starts PROD, will the lock file be enough to ensure integrity?   TEST *  TEST MDISKS                                             * *************                                             MDISK 740 3390 000 3339 RAM040 MWV ALL    VSETSW VSETSMW    PROD   * ****************     *  SHARED VOLUMES      * ****************      LINK TEST 740 740 MW    Ed Martin Aultman Health Foundation 330-588-4723 [EMAIL PROTECTED] ext. 40441 From: owner-[EMAIL PROTECTED] [mailto:owner-[EMAIL PROTECTED]] On Behalf Of Wakser, David Sent: Wednesday, September 06, 2006 10:58 AM To: VSE Discussion List Subject: VM directory entry for shared DASD   -- Note - this is cross-posted to VM list! All:         Please settle an argument: if a DASD volume is to be shared in WRITE mode between two VSE systems running under VM, should the MDISK statement specify MWV or MW?         I recall that the "V" is only needed (or desired) when you wish to invoke CP RESERVE/RELEASE. However, if a VSE lock file is being used (or there is some other method for ensuring integrity), then the "V" is not needed.         Can anyone settle this dispute? David Wakser InfoCrossing Confidentiality Note: This e-mail, including any attachment to it, may contain material that is confidential, proprietary, privileged and/or "Protected Health Information," within the meaning of the regulations under the Health Insurance Portability & Accountability Act of 1996. If it is not clear that you are the intended recipient, you are hereby notified that you have received this transmittal in error, and any review, dissemination, distribution or copying of this e-mail, including any attachment to it, is strictly prohibited. If you have received this e-mail in error, please immediately return it to the sender and delete it from your system. Thank you.