Saurabh, You have almost-certainly indentified the cause of your problem - it is NEVER, EVER safe to share the same CMS minidisk accessed in write-mode by more than one CMS user at the same time - it almost-guarantees that the disk file system will be damaged.
DASD sharing always requires the sharing systems to be aware that the DASD is shared and take measures to ensure that the data is not corrupted - these can be via hardware functions such as RESERVE / RELEASE or via software processes that use a communications link to agree amongst themselves which system has write-permission at any one instant. CMS contains no sharing mechanism at all for its minidisks (think of a CMS user as a virtual Personal Computer - write-sharing a minidisk is like connecting two personal computers that have no knowledge of each others' existence to the same hard drive!) If you wish to share data in write-mode among CMS users then you need to look at the CMS Shared File System which uses a server to co-ordinate the I/O among many CMS clients. (In this client/server setup, it's only the DATA that is shared - the actual DASD is only read/written by the server which (of course) has complete knowledge of which clients are accessing which data.) Sharing minidisk-containing volumes between separate z/VM systems requires a lot of care if it is to be successful. If you can tell us a little more about your configuration and how you run it I'm sure that we can offer you some suggestions about how to achieve what you wish to do but ... in the meantime ... yes, each PERFSVM requires a separate 191 (and 195) minidisk. Regards Jeff Gribbin
