raid setups fail due to mdadm.conf with explicit ARRAY statements and HOMEHOST !=any
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
debian-installer (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned | ||
Bug Description
Binary package hint: debian-installer
On systems that are set up statically mdadm.conf is often used to list the md devices that should be set up and the startup script just calls mdadm --assemble --scan.
But on systems oriented towards hotplug ability this prevents arrays from being assembled by the hotplug system.
Ubuntu has switched to set up complete (non-degraded) arrays automatically with udev rules. But any ARRAY line in mdadm.conf created during (package) installation prevents the hotplugging to work with other arrays.
As in general only complete (non-degraded) arrays should be run automatically, the automatic assembly will leave partial arrays that may be plugged in untouched, thus the system shoud be save even without the ARRAY restriction.
(The --no-degraded and --increamental options have been implemented with this hotplugging in mind.)
The installer should not create the ARRAY lines on udev+mdadm systems because this breaks further raid setups.
summary: |
- mdadm.conf with explicit ARRAY statements, and HOMEHOST !=any prevents - hotplug autodetection + mdadm.conf created with explicit ARRAY statements, and HOMEHOST !=any + prevents hotplug autodetection |
summary: |
- mdadm.conf with explicit ARRAY statements, and HOMEHOST !=any prevents - hotplug setup + raid setup fails due to mdadm.conf with explicit ARRAY statements and + HOMEHOST !=any |
description: | updated |
summary: |
- raid setup fails due to mdadm.conf with explicit ARRAY statements and + raid setups fail due to mdadm.conf with explicit ARRAY statements and HOMEHOST !=any |
On Hardy all distros (including server!) do not correctly implement Raid 1 together with crypted partitions or lvm.
The whole installation process requires a well thought out strategy taking into consideration that the initramfs of a degraded system might be inappropriate and that it is not possible to create a new image before the system is up again...
With degraded arrays it all depends on the type of raid.
For raid 1 (mirroring) the user might well decide to continue booting (automatically or after manual confirmation?).
For other raid types this is high risk, but in some special cases might be necessary.
See also bug Bug 33649 pending for more than 2 years.