Once upon a time, Chris Murphy <lists(a)colorremedies.com> said:
> For example, snmpd stores program-generated config in
/var/lib/net-snmp,
> which gets merged with config from /etc/snmp.
What's the exact consequence of deleting either /etc/snmp and
/var/lib/net-snmp - separately and together?
Delete either one and permanent config is lost. Admin config is in
/etc/snmp and program-generated config (sometimes based on admin config)
/var/lib/net-snmp.
If there's program-generated config in /var/lib/net-snmp, why
can't it
regenerate it when its missing?
The documented way to create SNMPv3 users puts the config in
/var/lib/net-snmp. The system serial number and engine ID are randomly
generated at the first startup and saved in /var/lib/net-snmp (but are
then supposed to stay constant for the life of the system). Persistent
network interface IDs are stored in /var/lib/net-snmp. Those are just a
few things I know of.
Deleting /var/lib/net-snmp/snmpd.conf means making the agent look like a
new system, with new IDs, a renumbered interface table, and loss of
SNMPv3 users.
And that's just one thing I know of that uses /var in such a manner.
How many other things expect /var to be an integrated part of the OS?
Making /usr "special" and throwing all other directories away is a bad
plan, only sustainable for a niche subset of packages. If snapshots are
so important, an actual integrated plan for the WHOLE OS needs to be
created, not just by recreating all the parts of / that someone is
interested in under /usr.
--
Chris Adams <linux(a)cmadams.net>