[Bug 1650300] Re: ubuntu-installer/partman does not properly detect partitions on FBA device

[Dimitri John Ledkov]

"I.e. one could check whether the disk is of type dasd_fba and in this
case not request a dasd label." but how would one do that in partman-
base? given that parted does report "dasd" type to partman. Note that
partman-partitioning ultimately decides what the default partition table
is, and users can override that. What I have uploaded is a whitelist,
thus if somebody export FBA via virtio, it will result in using dasd
partition table =(. However, the combination of FBA and KVM is niche no?
(as in running kvm, in z/VM, with FBA pass-through virtio devices)

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to partman-partitioning in Ubuntu.
https://bugs.launchpad.net/bugs/1650300

Title:
  ubuntu-installer/partman does not properly detect partitions on FBA
  device

Status in Ubuntu on IBM z Systems:
  Confirmed
Status in partman-partitioning package in Ubuntu:
  Fix Released
Status in partman-partitioning source package in Xenial:
  Triaged
Status in partman-partitioning source package in Yakkety:
  Triaged

Bug description:
  [Impact]
  * multipartition installations on DASD-FBA use wrong partition table, resulting in userspace tools not recognising the partitions that kernel uses on those drives

  [Testcase]
  * install ubuntu using manual partitioning onto DASD-FBA drive with two partitions e.g. 500M for /boot and / for the rest.
  * re-start the installer again
  * observe that in manual partitioning both partitions are correctly detected and for example reuse of partition #2 is offered.

  I installed Ubuntu 16.04.1 on an FBA device. When the partman menu appeared, I created a new partition table on DASD 0.0.ede0 (FBA), and then I created two partitions: 0.7G ext4 for /boot and 10G ext4 for /.
  Installation proceeded ok, and the system ipled from EDEV EDE0.  All fine.

  During a 2nd installation on the same device the following problem occured:
  After activation of the previously installed EDEV disk, partman shows one single full size partition, which is not correct:
  DASD 0.0.ede0 (FBA ) - 10.7 GB IBM S390 DASD drive
  >     #1    10.7 GB

  while kernel has the correct info:
  ~ # cat /proc/partitions |grep dasd
    94        0   10485760 dasda
    94        1     683584 dasda1
    94        2    9801984 dasda2
  Continuing with the installation from here results in a system IPL that ends up in an initramfs, since the rootfs could not be mounted due to an incorrect partition table.

  Attaching syslog.

  Until this bug is fixed, I recommend to describe the workaround (when
  installing on EDEV DASD it is highly recommended to create an empty
  partition table on the entire device before partitioning) in the
  release notes.

  Maybe you can have a look info LTC bug 137464 / LP1548411 which
  described a similar problem with vdisks under KVM.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu-z-systems/+bug/1650300/+subscriptions