> There is no mention in the General Information manual what > this support of > for or if there are any restrictions. I am going to guess > that (almost) any > SCSI device can then be accessed by Linux for zSeries. I > would speculate > that this may be geared for large capacity tape device > support, so that Linux > can be used as a network backup server.
In fact, the demonstration at LinuxWorld was a CD-RW being driven by a Linux guest as well as a LTO drive. > On Sunday 19 May 2002 02:02 pm, you wrote: > > This is confusing....can you expand on your reply... > > If I still need ECKD for Z/VM, > > then how does this new feature benefit > > the Linux environment...since most of us > > will be running Linux under z/VM?? Consider that you can dedicate devices to guests, and then VM gets out of the way as much as possible. This allows the guest to do things that VM doesn't know how to do directly. AFAIK, this is pretty standard process for new function in the VM world -- the first release of a new technology is usually guest-only support, then the following release allows VM to use it natively. For now, you need enough ECKD disk to store the VM system, the VM paging/spooling disks, and a few small minidisks for booting your Linux guests, since the FBA boot support for Linux hasn't been updated in a while. The rest of your disk subsystem can be (from the VM perspective) ATTACHed and/or DEDICATEd to Linux guests directly, and they can do FCP to their hearts content without VM having to know anything about it. This would allow the Linux guests to get at the data. In time, VM will probably be able to cope with FCP disks directly -- VM and VSE were the only IBM OSes ever to really understand FBA, and I think that VM may be the only one left that still does understand booting from FBA (somebody in VSE-land correct me if I'm wrong). Still, FCP disk is different from a 3370, so some of the boot code for VM will need to get rewritten. This will take time, and given the recent staffing cuts at IBM, I suspect this may be a while in coming. This requirement for ECKD disk seems to be one of the flaws in the z800 (along with a lack of an integrated console controller). It seems like adding some internal disk would be a good improvement; doesn't have to be high-performance, but enough to IPL the system would be a big plus....
