MaaS deployment generates incorrect multipath bindings

[Stefan Bader]

Currently MaaS (1.9.2+bzr4568-0ubuntu1 (trusty1)) deployments of Xenial on ppc64el fail to finish because the reboot into the freshly deployed system cannot get the mpath0 multipath volume up.

This is because the installer generates an incorrect /etc/multipath/bindings. The generated file is:

# This file was created by curtin while installing the system.
mpath0 1IBM IPR-0 5EC3390000000080
# End of content generated by curtin.
# Everything below is maintained by multipath subsystem.

However the output of /lib/udev/scsi_id --export --whitelisted -d <device> changed. For example

ID_SCSI=1
ID_VENDOR=IBM
ID_VENDOR_ENC=IBM\x20\x20\x20\x20\x20
ID_MODEL=IPR-0_5EC33900
ID_MODEL_ENC=IPR-0\x20\x20\x205EC33900
ID_REVISION=
ID_TYPE=disk
ID_SERIAL=1IBM_IPR-0_5EC3390000000080
ID_SERIAL_SHORT=IBM_IPR-0_5EC3390000000080
ID_TARGET_PORT=c339

The ID_SERIAL matches the real string used to create /dev/disk/by-id/... and the multipath device-mapper volumes. So the bindings file does not create a mpath0 volume and the root filesystem is not found.

Temporary workaround (for above example):

multipath -F
echo "mpath0 1IBM_IPR-0_5EC3390000000080" /etc/multipath/bindings
multipath
exit

[Stefan Bader (smb)]

Same (or similar problem) on a Wily deployment. Only that there the non working mapping is followed by correct ones but different alias names:

cat /etc/multipath/bindings
# This file was created by curtin while installing the system.
mpath0 1IBM IPR-0 5EC3390000000080
# End of content generated by curtin.
# Everything below is maintained by multipath subsystem.
mpatha 1IBM_IPR-0_5EC3390000000080
mpathb 1IBM_IPR-0_5EC3390000000060
mpathc 1IBM_IPR-0_5EC3390000000040
mpathd 1IBM_IPR-0_5EC3390000000020
mpathe 1IBM_IPR-0_5EC33900000000C0
mpathf 1IBM_IPR-0_5EC33900000000A0
(initramfs) /lib/udev/scsi_id -g --export /dev/sda
ID_SCSI=1
ID_VENDOR=IBM
ID_VENDOR_ENC=IBM\x20\x20\x20\x20\x20
ID_MODEL=IPR-0_5EC33900
ID_MODEL_ENC=IPR-0\x20\x20\x205EC33900
ID_REVISION=
ID_TYPE=disk
ID_SERIAL=1IBM_IPR-0_5EC3390000000080
ID_SERIAL_SHORT=IBM_IPR-0_5EC3390000000080
ID_TARGET_PORT=c339