> The Linux kernel does not consider an LDL-format disk to be "unpartitioned".
But the partition you see is a phantom. And you can use an LDL-format disk as if it were "unpartitioned". We're battling semantics, or something along those lines. I previously used the term "partition zero". People did not seem to understand that. The "whole disk" seems to work. It's good to be able to use the whole disk, if only for reduced complexity. It's bad when the bootstrap clobbers the filesystem. Here's a rough diagram: + ------------------------- + CDL + LDL + FBA + | filesystem in partition 0 | --- | -Y- | -Y- | | bootable with fs in part0 | --- | --- | -Y- | | filesystem in partition 1 | -Y- | -Y- | -Y- | | bootable with fs in part1 | -Y- | -Y- | -Y- | | filesystem in partition 2 | -Y- | --- | --- | | bootable with fs in part2 | -Y- | --- | --- | | filesystem in partition 3 | -Y- | --- | --- | | bootable with fs in part3 | -Y- | --- | --- | + ------------------------- + --- + --- + --- + | works with DIAG250 driver | --- | -Y- | -Y- | + ------------------------- + --- + --- + --- + | --- external transparency | --- | --- | -Y- | + ------------------------- + --- + --- + --- + (Looks really bad with my proportional font email interface. See below for a Googoo doc.) I advocate use of partition zero for filesystems. It is a little-known and underutilized feature of zLinux just like the CMS RESERVEd file. Put a filesystem on /dev/dasdq, reboot, and you'll still see a /dev/dasdq1 partition. But the filesystem survives in /dev/dasdq. This is a Good Thing. In this case, just ignore /dev/dasdq1. It is an artifact of the driver. So ... to answer the question about what Rick is asking for, I want the "bootable with fs in part0" to change to Y for LDL. It requires a ZIPL change. Another little-known and underutilized fact is the internal/external transparency of FBA storage. (Talk about reduced complexity!) I will spare the group and not discuss it further except to say that it is ... just another: Something that doesn't get advertised enough, kind of like CMS RESERVE. I have attempted to collect some of this info into a spread sheet: http://spreadsheets.google.com/ccc?key=0ArAkQhEvbQZfdEhxZDhLNEEwU0dvVlJBUmVXVnJ6c1E Not sure how to fit use of CMS RESERVE on that. Suggestions? -- R; <>< Rick Troth Velocity Software http://www.velocitysoftware.com/ On Thu, Jan 6, 2011 at 16:47, Stephen Powell <zlinux...@wowway.com> wrote: > On Thu, 06 Jan 2011 16:10:36 -0500 (EST), Richard Troth wrote: >> >> The "problem" is that one cannot boot from an unpartitioned CKD disk >> (LDL) even though one can boot from an unpartitioned FBA disk. >> Partition tables are not required for other disks and bootstraps. Why >> should they be required for mainframe disks and bootstraps? > > The Linux kernel does not consider an LDL-format disk to be "unpartitioned". > If you format a disk with dasdfmt using "-d ldl" (and other appropriate > parameters), then the disk has been implicitly partitioned, as far as > the Linux kernel is concerned. Assuming CKD DASD, the implicit partition > will begin with the fourth physical block. (The first two blocks are > reserved for IPL records, the third block is the volume label.) > > I haven't tested your exact scenario, but here's what I have tested. > I have a Linux machine that runs in a virtual machine under z/VM. > It has four disks, as follows: > > device block mount > number special point > file > ------ ------- ----- > 0200 /dev/dasda > /dev/dasda1 / > 0201 /dev/dasdb > /dev/dasdb1 /boot > 0202 /dev/dasdc > /dev/dasdc1 /home > 0203 /dev/dasdd > /dev/dasdd1 swap > > All four of the disks are CMS reserved minidisks. All of them use > the DIAG driver except 0201, which uses the ECKD driver. The > boot device is 0201. Linux is started by > > IPL 0201 > > It works great. I've been doing it for years. What's the problem? > > (0201 has to use the ECKD driver because zipl does not support > writing IPL records to a device controlled by the DIAG driver) > > -- > .''`. Stephen Powell > : :' : > `. `'` > `- > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
