Ron, If you have HDS DASD there is a mainframe security feature that allows you to mask logical volumes from specific LPARs. The idea is that if you get it wrong in the OS the storage will stop you from shooting yourself in the foot.
If you don't have HDS DASD then you may want to ask if your vendor has a similar feature. It's not really a shameless plug, as I think (I'm not in sales) it comes with the basic operating system for our storage. I have never used it and I have no idea how simple or not so simple it is to use. This was topical for me as we are changing device numbers all the time in the labs, and occasionally z/VM will have hold of a volume we are trying to get offline to all systems. Usually at sleep o'clock in the morning, so I'm thinking of using it for my test boxes. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@bama.ua.edu] On > Behalf Of Ron MacRae > Sent: Wednesday, May 16, 2012 1:04 PM > To: IBM-MAIN@bama.ua.edu > Subject: [IBM-MAIN] Co-existance of z/OS and z/VM on same DASD farm > > Hi all, > We are currently an exclusively z/OS site with multiple LPARs sharing a > single IOCDS and DASD farm. We are about to install z/VM in a new LPAR and > I'm worried about both OSs sharing the same DASD farm. They will not be > sharing at the volume level. > > I've read through the install doc and it all seems fine, you tell the install > process 6 or 9 unit adresses and it goes and loads stuff onto them and then > you IPL. There is no mention of modifying other volumes, however there are > include and exclude unit address lists that you can specify to define what > z/VM will try to look at, which presumably you can't get at until after the > basic install and IPL. Also z/VM can issue sense commands to determine what > devices are out there. > > The reason I'm worried is that in a previous life, over 30 years ago, my > previous company attempted to do the same between an VM system and a > DOS/VSE system. This was a long time ago on a real machine in pre LPAR > days. > When they brought up VM for the first time it objected to the VSE VTOCs it > found and rewrote them as OS VTOCs and we lost the whole DASD farm. > Management were not best pleased. I wasn't directly involved at that time > so I'm not 100% sure of my facts here and perhaps the guys who did this did > something wrong, however my worry still remains. > > My question is - Do we have to isolate z/VM from the z/OS volumes or will > z/VM play nice and leave stuff alone? > > I just want to double check that VM will only touch the 6 volumes it is given at > install time. > > Regards, Ron MacRae. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > lists...@bama.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
