Booting LXDE from an 8MB usb stick formatted as 1 ext4 partition, on shutting down, after the messages
Unmounting local file systems
Deactivating LVM volume grouporm
I get ~30 messages of the form
WARNING Decice /dev/<device> not initialized in udev database even after waiting 10000000 microseconds
These occur at 10 second intervals, delaying shutdown by ~5 minutes.
The first few values of <device> are
sda
avgo/root
loop1
sda1
avg0/home
loop2
avg0/ubuntu
loop3
sda3