Comment 47 for bug 571707

The problem is a bit strange. Watching mountall on inside a screen with -v shows that it is noticing the fsck finishing and it goes on to remounting "/" and mounting all the other filesystem components. For example I see:
fsck from util-linux-ng 2.17.2
ubuntu1004: 149164/494832 files (0.1% non-contiguous), 754483/1984027 blocks
fsck / [3034] exited normally
remounting /
...
local 3/3 remote 0/0 virtual 11/11 swap 0/0

However it is hanging waiting for something to finish.

Running gdb on it shows the last thing gdb can spot it doing is ply_boot_client_flush(). On plymouth screen, the percentage count goes up very slowly. A few seconds after killing plymouthd mountall spews a lot of errors before finally saying it has disconnected from plymouth.

If I had to hazard a guess I'd say a huge backlog is occurring...