Le 21/11/2018 à 17:11, Alessandro Selli a écrit :
>> 1) A separate /usr serves no practical purpose on a Debian/Devuan system
>   Yes it does, and they were already listed:
>
>
> 1) mounting /usr with different mount options (like barrier, ro, nodev etc);


chown -R a-w /bin
chown -R a-w /sbin
chown -R a-w /lib


>
> 2) having /usr mounted over the network keeping / local;
>
> 3) having a /usr partition shared by several local installs that are
> booted on different / filesystems;
>
> 4) having the smallest possible / filesystem to ease recovery of a
> botched system.
>
>
    This is all fine with a custom OS, not when it is maintained by a
package manager. Inconsistencies between the different filesystems on
which the package manager operates will just make it mad. Your OS may
still be usable but not updatable. I have realized this after two
decades of crazy partitionning. /home should definitely be separated and
well protected (RAID where possible, backups), /usr/local (or /local)
may as well, /opt also,since Debian does not use it. But the part of the
OS (which is managed by dpkg) better stays on one single partition.
/run, /tmp are well on tmpfs. An efficient way to secure the OS is to
clone it on another partition.

    Didier