o1bigtenor:
> Background:
> Reading about the upcoming necessity of moving to 'usr merge'.

The usr-merge is severly nochanlant to people running systems at
remote places, especially if there a lot of them.

> My boxen (for at least the last 12 years if not longer) I run separate
> partitions for (last number of years only this new one) /efi, /boot ,
> /root (yes I know its a redundancy but it gets the label of /root ),
> /swap, /usr. /var, and /home. (Not going into the
> reasoning for such.)
>
> Question:
> What am I supposed to do so that my system will continue to boot with
> this change
> to /usr merge?

For your system to survive this madness it to take control of the
booting process yourself.
You can do that by e.g. building and installing busybox or similar.
With busybox init, make a /etc/inittab like:

##########
::sysinit:/etc/rcS

tty1:12345:respawn:/sbin/agetty --noclear 38400 tty1 linux
tty2:12345:respawn:/sbin/agetty --noclear 38400 tty2 linux
tty3:2345:respawn:/sbin/agetty --noclear 38400 tty3 linux
tty4:2345:respawn:/sbin/agetty --noclear 38400 tty4 linux
tty5:2345:respawn:/sbin/agetty --noclear 38400 tty5 linux
tty6:2345:respawn:/sbin/agetty --noclear 38400 tty6 linux

#::ctrlaltdel:/sbin/shutdown -r now
::ctrlaltdel:/root/bin/Off
##########

then create a file /etc/rcS basically replacing the whole
sysvinig or whatever bootup, just retrace your current bootup
process and put that in your new rcS. An example start of such
a file (and yes this is for a system without udev):

##########
#!/bin/sh

#sleep 3
#/sbin/sulogin -t 5

/bin/busybox mount /proc
/bin/busybox mount /sys
/bin/busybox mount /config
/bin/busybox mount /dev/pts

/bin/busybox mount /tmp
/bin/busybox mount /run
/bin/mkdir /run/lock
/bin/busybox mount /run/lock
/bin/mkdir /run/shm
/bin/busybox mount /run/shm
/bin/mkdir /run/sshd
/bin/mkdir /run/dbus
/bin/mkdir /run/postgresql
/bin/mkdir /run/proftpd
/bin/chown -R postgres.postgres /run/postgresql/

/sbin/fsck -p -C -V -t ext4 /dev/md2
if [ "$?" -gt 1 ]
then
/sbin/sulogin -t 5
fi

/bin/hostname `cat /etc/hostname`

/sbin/hwclock -u -s

#/sbin/mdadm -A /dev/md16 /dev/sda6 /dev/sdb6
for i in 7 6
do
/sbin/mdadm -A /dev/md$i /dev/sdc$i
done
for i in 5 4 3 1
do
echo mdadm -A /dev/md$i /dev/sda$i /dev/sdb$i
/sbin/mdadm -A /dev/md$i /dev/sda$i /dev/sdb$i
done

/sbin/fsck -p -C -V -R -A
if [ "$?" -gt 1 ]
then
/sbin/sulogin -t 5
fi

/bin/busybox mount -a
/sbin/swapon -a

/usr/sbin/adjtimex -t 10000 -f 403859

##########

Regards,
/Karl Hammar