I am currently running Ubuntu 12.04 and have a RAID setup with the boot-degraded option. If I upgrade to 14.04 will the boot-degraded option remain? I manage this server remotely and would hate to perform this upgrade only to have to take a road trip afterward to set the boot-degraded flag myself.
3 Answers
The BOOT_DEGRADED variable is not used or supported in Ubuntu 14.04 or any other system with mdadm-3.2.5-5ubuntu3 or later (see change "Drop degraded array questions, since the degraded check results in false negatives "). The system should always boot even on a degraded array.
But - I read about various problems with it - https://bugs.launchpad.net/ubuntu/+source/mdadm/+bug/1341312.
Just confirming that the BOOT_DEGRADED option is still supported in 14.04, and is still required if you want your server to boot automatically when a disk fails.
Source: anecdotal evidence. Just had a disk fail, and the server would drop to a initramfs shell, where I had to manually --force assemble the array.
Executing
echo 'BOOT_DEGRADED=true' > /etc/initramfs-tools/conf.d/mdadm && update-initramfs -k all -u
as root and rebooting (to verify) did result in Ubuntu booting all the way, even with the still-degraded array.
There is no harm in re-setting the boot degraded flag after update, just to be sure, but it is unlikely to be deleted.
echo 'BOOT_DEGRADED=true' > /etc/initramfs-tools/conf.d/mdadm && update-initramfs -k all -u
The answer posted by "undefine" is incorrect (except in that he partially retracted it), and the one posted by "Stefan" correct, at least as is true of 16.04.
