On Sun, 16 Aug 2015 08:28:42 -0400 (EDT), Philipp Kern wrote: > ... > However it then turned out that I needed to hack the zipl config to > make the kernel see the DASD from within the initrd. > > [ 0.066844] Kernel command line: root=/dev/sysvg/root > dasd_mod.dasd=0.0.0100 BOOT_IMAGE=0
That's because sysconfig-hardware isn't in the initial RAM file system, and therefore doesn't bring DASD volumes online until the permanent root file system has been mounted. If the permanent root file system is a partition on a physical volume, there is exception code in /usr/share/initramfs-tools/scripts/init-premount/sysconfig_hardware to bring that specific volume online early, but only if the root device is specified in zipl via the form root=/dev/disk/by-path/ccw-0.0.xxxx-partz where xxxx is the device number and z is the partition number. It must be in this form so that /usr/share/initramfs-tools/scripts/init-premount/sysconfig_hardware knows the device number and can bring it online via echo 1 >/sys/bus/ccw/devices/0.0.xxxx/online This is one reason, but not the only reason, why I advised the OP not to make the root file system a logical volume. On my systems, I add sysconfig-hardware to the initial RAM file system, using the method described in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=621080 but of course this cannot be done until *after* installation. The main reason that I do it is so that I can specifiy the root file system in zipl as root=UUID=... which will only work if all the DASD volumes have been brought online already, and therefore udev has found the volumes and their partitions and has created symbolic links for them in /dev/disk. This makes the boot process much closer to how it works on all other hardware platforms that Debian supports. -- .''`. Stephen Powell <[email protected]> : :' : `. `'` `-
