Subject: Re: nore on disk stats
To: None <perry@piermont.com>
From: Jason Thorpe <thorpej@SJ.Xenotropic.COM>
List: tech-kern
Date: 11/14/1995 13:37:24
On Tue, 14 Nov 1995 15:09:31 -0500
"Perry E. Metzger" <perry@piermont.com> wrote:
> to get that sort of information out without running any daemons on the
> machine -- indeed, all my machines at home listen to the network
> minimally if at all. This is important for security at many
> sites. Besides, the idea of making system utilities like netstat
> dependant on having a daemon running just plain feels bad.
That doesn't mean you have to run snmpd. Just that sysctl() takes those
arguments...
> On the other hand, having netstat and other utilities (including ps
> and others) use sysctl() could be potentially really good, both from a
> point of view of cleanliness of interface and because such utilities
> might not need suid privs any more, which can improve security a lot.
ps, et al don't need to be setuid. instead, they're setgid kmem, and
group kmem has read-only access to the kvm space.
I think, though, that people seem to be missing one of the _really_
important features of using libkvm in these cases: it works on dead
kernels/crash dumps. Try using a procfs-based ps(1) to look for the
process that made the last kernel panic and dump core. So, if you have
to keep the libkvm interface around anyhow, why add a completely
different and less flexible interface?
> Again, although this is technically what the standards say you should
> do, I'm not sure it actually feels good. I've been in environments
> where people have experimented with lots of remote management tools,
> and SNMP is great for getting stats off of routers but lousy for
> actually altering their configurations -- and it seems like a lose for
> running machines.
I'd tend to agree. Community string are somewhat less than secure, but
you can always configure the agent to allow read-only access.
------------------------------------------------------------------------------
Jason R. Thorpe thorpej@Xenotropic.COM
Just me and my collection of obsolete computer gear(s).