There are no differences with respect to the underlying kernel state.
There is a minor difference with respect to the operation of the
mount command: it keeps track of its actions in
/etc/mtab, so running
chroot will update a different
You could also use
mount --bind /proc ./my_chroot/proc. As far as I know, there is no practical difference between that and
mount -t proc none ./mychroot/proc: you can mount the
proc filesystem as many times as you like, and mount options are ignored.
mount --bind will prevent you from unmounting the filesystem on
/proc outside the chroot, but that should never happen anyway.
As an aside, I would recommend
mount -t proc proc …/proc because seeing
proc in the device field in a
mtab or in
/proc/mounts is clearer than seeing