Bug#222844: Partitioner /should/ allow partitioning while partitions mounted...
... but should then realise that this requires a reboot to reread the
I recently wanted to install a laptop that couldn't detect the cdrom
drive after boot, so I followed the hard drive instructions and used
grub to boot the installer from a windows partition on the same hard
disk. It would be useful to have the partitioner let you do this, as it
provides an extra bootstrapping procedure that may allow you to install
on something that you otherwise couldn't. AIUI there is no harm in
partitioning whilst a partition is mounted as long as you don't touch
that partition, it's just that the kernel does not reread the partition
table in this case.
In my case the mkfses failed, of course, but simply rebooting and
skipping partitioning worked fine.