chown (was: at files and permissions)

J Greely jgreely at oz.cis.ohio-state.edu
Thu Jul 13 03:55:52 AEST 1989


In article <4958 at ficc.uu.net> peter at ficc.uu.net (Peter da Silva) writes:
   How do you allocate quotas? sum(all quotas) == free space on disk? Then you
   might as well give each user a seperate partition. sum(all quotas) < free
   space? Then you can still run out of disk space.

(you do mean sum > space on that last point, don't you?)  If we could
use the Berkeley quota system, we would.  Unfortunately, it doesn't
work correctly when you mix NFS and multiple vendors.  How would we
set it up if we did use it?
    Sum(soft quotas) <= free space  (about 90% sounds good)
    Sum(hard quotas) >  free space

Set the soft quotas to a slightly generous estimate for each user
type, and set the hard quotas to a very generous estimate (1.5-2.5
times the soft quota).  If soft quotas are properly chosen, most users
will remain below them, leaving free space for the people who need to
go over temporarily.  If someone needs a larger quota, and there's not
enough room on the current partition, you juggle people around
partitions until they all fit.

   Don't try to make the quota system unbreakable. If someone wants to be a
   bad boy, you'll catch them. Don't burn honest users... you're not a cop.

(Does that imply that cops burn honest citizens?)  

We can't use real quotas, so we're stuck with a fake quota system (set
quotas for each user on each filesystem, run quot and compare, mail
warnings and summary).  When that isn't enough, things get rude.  More
than once, I *have* felt like a cop, tracking down an anonymous grad
student who logs in once a week, doesn't read his mail, and has a ten
meg file named thesis-proj.out.  Should I delete it?  Compress it?
Dump it to tape?  Pick on someone else, and find out later it was
garbage?  Nuke it, and find out that it was in use by a program vital
to his research?

  And of course, not everyone who drastically exceeds their quota is a
"bad boy".  Ignorance and laziness are tied as the primary reasons for
unreasonable disk usage around here.


			The steady state of disks is full.
				-- Ken Thompson
-=-
J Greely (jgreely at cis.ohio-state.edu; osu-cis!jgreely)



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