shared between virtual machines /usr

Question

Debian

It is planned to have several virtual machines under Xen on debian or server ubunt.
I would like to make one partition /usr for all virtual machines (and maybe even /bin/sbin/lib).

What rake can arise here?

So far I see only one thing:
adding / updating some package can lead to changes in /etc and /var which will need to be somehow cleverly transferred to another section.

Answer 1

Get a lot of rakes.
And reduce to nothing all the advantages of virtualization.
You won't save much on usr

Answer 2

what's the point in that? can it be better to do thin clients?

Answer 3

Try using filesystem-level compression (something like fusecompress). You will have many identical files, so you can hope for good compression.