Comment 2 for bug 559761

I'm seeing a variation on this, with significant similarities - I'll try the method above.

In my case, Plymouth comes up, and tells me that it will check all the disks, but then halts at 90% or 8% (depending on whether it checks one or both of the disks). It provides the option of pressing C to cancel the check, but does not respond if C is pressed (shift + c or just c).

If I press escape, I get several screens full of "udevd[xxx]: SYSFS{}= will be removed in a future udev version, please use ATTR{}= to match the event device, or ATTRS= to match a parent device, in /etc/udev/rules.d/65-libmatp.rules:89" or variations upon that theme.

Often I also get a "ureadahead-other main process terminated with status 4" message or two

At end, it also drops several instances of the aforementioned "mountall: Plymouth command failed".

At which point, the computer appears to hang, and no further progress is made towards booting.

I tested other kernel versions, and I get roughly the same series of events.