"2.1. Lack of Flexibility
"Lack of flexibility is obvious for many reasons. First, if the
end-user wants another layout (for example he wants to resize the
root file-system, or he wants to use a separate /tmp file-system),
he will have to reboot the system and to use a partitioning
software (from a livecd for example). He will have to take care of
his data since re-partitioning is a brute-force operation the
operating system is not aware of.
"Also, if the end-user wants to add some storage (for example a
new hard drive), he will end up modifying the system layout
(/etc/fstab) and after some while, his system will just depend on
the underlying storage layout (number, and location of hard drives,
partitions, and so on).
"By the way, having separate partitions for your data (/home but
also all audio, video, database, ...) makes much easier the
changing of the system (for example from one Linux distribution to
another). It makes also the sharing of data between operating
systems (BSD, OpenSolaris, Linux and even Windows) easier and
safer. But this is another story.
"A good option is to use Logical Volume Management (LVM). LVM
solves the flexibility problem in a very nice way, as we will see.
The good news is that most modern distributions support LVM and
some use it by default. LVM adds an abstraction layer on top of the
hardware removing hard dependencies between the OS (/etc/fstab) and
the underlying storage devices (/dev/hda, /dev/sda, and others).
This means that you may change the layout of storage -- adding and
removing hard drives -- without disturbing your system. The main
problem of LVM, as far as I know, is that you may have trouble
reading an LVM volume from other operating systems."