On Tue, 2003-06-10 at 09:13, McKown, John wrote: > I have a general administration / setup question for people who are running > multiple Linux/390 systems under z/VM. Do all your Linux instances use the > same virtual addresses for things like DASD, regardless of the actual device > address?
Yes. It may vary by site, but I like to set up a scheme where, for example, 150 is /, 151 is swap, 152 is /usr, 153 is /opt, and 154 is /usr/local, where any guest may or may not have a 153 or 154 depending on what it needs to do and whether it needs its own DASD for it (I'm also a big fan of sharing /usr read-only). > Or do you find it "better" to make the virtual DASD address match > the actual device address? I'm tending towards making all Linux/390 > instances use the same set of virtual DASD addresses, which are not even > related to the "real" DASD addresses. I think this would be easier to > maintain and "clone" new instances. It is. > Do you even try to make the Linux DASD > addresses "look like" the actual device numbers, or do you simply have a > range of virtual DASD addresses that you assign to physical devices. I'm > using MDISK statements for Linux DASD. Basically, so far, I give each > instance (OK, I only have one so far), the entire device OTHER THAN the > first cylinder. Sorry, but I don't trust the Linux administrator to not > destroy the DASD label, so this protects it from any mistakes. Oh, I'm the > OS/390 and z/VM (new) sysprog. I am familar with Linux on Intel and did help > the Linux administrator set up the initial Linux/390 system because she is > not s390 literate. And I had actually done a SuSE s390 install at home under > Hercules/390. So I was the "expert". This is what I do. I don't generally like dedicated DASD; let VM manage it, is my usual advice. The nice thing about VM is that you *don't* have to care about the physical devices; pick a range you like, and I tend to think you should pick a range that isn't even close to the real DASD range, so you know, just from the device address/site convention, that you're talking Linux filesystems on minidisks. Adam
