Comment 3 for bug 1335642

Hello all!

Problem with same symptom (loops on the same massage).
My system boots on a USB stick and has 4 sata disks in RAID 5 with 3 active and a hot spare. One of the disks failed and was kicked
out of the array (probably a transient failure, needs further investigation). For some reason I then lost all access means to the machine, although Apache was still responding. The machine did not react to an ACPI reboot and I hard rebooted it while it was rebuilding the RAID on the spare disk ...
It should have come up fine on 2 disks, but instead was stuck with the four line beginning with "Incrementally starting RAID arrays".
Some keying after boot in recovery mode lets me down to a root shell on initdisk. I can see that the RAID is active forced read only on two disks out of three. If I stop it and assemble it again from the working disks, it is just active, ready to go and can be mounted.
I have re-added the failed and spare partitions: if the failing one fails again rebuilding will proceed on the hot spare. Reconstruction of the missing RAID component is ongoing.

I have operated Linux RAID setups for many years and I have had several disk failures, some transient, some final. The boot scripts can handle that in 10.04 LTS and 12.04 LTS. In 14.04 LTS something changed: it may be mdadm choosing by default to assemble the array read only?

Hoping to provide useful information.