On Wednesday, 08/14/2002 at 11:39 AST, [EMAIL PROTECTED] wrote: > Currently running RH 7.2 in lpar mode (kernel: 2.4.9-37tape). We may be > getting z/VM in the future, which we've never used before. At least at > first look at the Building Linux Systems under IBM VM book, I'm confused > about the concept of minidisks. Do 3390 volumes have to be formatted > any differently in the z/VM enviroment than they would for a linux image > running LPAR mode? I guess what I'm asking is, apart from networking > stuff, can I expect to be able to define existing linux dasd volumes to > z/VM, login the guest and have the image boot? Or will I have to go > through some process to migrating the data to the minidisks so that they > work under z/VM? > > Sorry if the question doesn't make much sense, I'm still trying to get > my head around this stuff. Any pointers are appreciated. > ~ Daniel
Daniel, the volumes are formatted the same. A minidisk is simply a "partition" on the disk that is assigned to a VM user (virtual machine). In this way, a large volume can be carved up into smaller units that can help reduce wasted space on a volume. It also is the basis for the sharing of those "partitions" among several virtual machine. It is a similar concept to sharing a volume among LPARs, with the addition of secure partitioning of the volume. One slight difference with minidisks is that physical cylinder 0 on the volume is usually not part of the collection of minidisks on the volume. Rather, it contains the real, physical, volser that will be seen by the VM Control Program and it is kept safe from the poking fingers of virtual machines. To answer your specific question, yes, you can take an existing 3390 volume and "dedicate" it (a VM term) to a specific virtual machine. The virtual machine has complete control over the volume, and do the same things that it did in an LPAR. However, this is separate from the concept and use of minidisks, where the *system*, not a virtual machine, owns the volume. Alan Altmark Sr. Software Engineer IBM z/VM Development
