Hannes Reinecke wrote:
So back to the zipl question, it might be an idea to support initially
the SCSI disk layout only. This has the advantage of being far simpler
as the DASD disk layout and should be pretty straightforward to handle.
Issue is, the dasd disk layout is made for dasds. For eckd, the boot
code assumes variable blocksize, and the loader uses channel programs.
For both eckd and fba volumes, it assumes IBM disklabels and FICON
channel programs. Virt-IO disks do have an msdos-style partition table
as opposed to this.
That said, you'd need proper virtualiztion of a ficon dasd so that the
guest could possibly run the dasd boot code. Virt-IO disks otoh are
fixed block, have an msdos-style partition table, no channel programs,
and thus look just like scsi disks with a different interface.
Therefore, I think scsi boot is right for virt-IO disks. And zipl does
already create this layout in the version found in Sles11 and FC12.