We also do share some volumes amongst all our VM systems. On thses shared packs, we do define all minidisks on all VM systems and have an exec that nightly checks that all MDISKs on those voumes are in fact identical. To protect ourselves from accidents, we enabled XLINK (part of VM's CSE functions). XLINK will avoid that two VM systems have concurrent conflicting links. Just like that a simple "LINK xxx vdev vdev M" can fail with a message "xxx vdev not linked, R/W by uid", CP can then respond "xxx vdev not linked, R/W by VMxyz" What you need to to is define a table with all your VM systems in SYSTEM CONFIG, include the volsers in some XLINK other statement in SYSTEM CONFIG, issue some XLINK FORMAT command to format an area on the shared volumes, protect this area by some $xxx$ minidisk so that you do not accidentally define a user mdisk on top of it.
The only drawback is that you must IPL to make it active; there are no CP commands to dynamically define/change the SYSTEM CONFIG statements. Last but not least: define the volumes as SHARED (on RDEVICE in SYSTEM CONFIG, or with CP SET SHARED ON), so CP will turn off MDC for those volumes. Kris, IBM Belgium, VM customer support "Dusha, Cecelia Ms. WHS/ITMD" <[EMAIL PROTECTED]> Sent by: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU> 2006-08-03 10:35 Please respond to The IBM z/VM Operating System To IBMVM@LISTSERV.UARK.EDU cc Subject Shared Volumes Hello, I would like to share a volume on multiple zVM systems. Each system would have different area on the volume they could write to, the other areas would be read only. Each system needs to be able to write to this volume at the same time. Is this do-able? If so, how is this done? Please advice. Thank you. Cecelia Dusha
