[Kolab-devel] (fwd) how to deal with quotas / suggested feature "monthly quota increase"

Gavin McCullagh gavin.mccullagh at gcd.ie
Thu Sep 2 17:39:55 CEST 2010


On Thu, 02 Sep 2010, Jeroen van Meeuwen (Kolab Systems) wrote:

> In an environment of 1k users with 1GB quota, which I've been running on the 
> side for 5 years, the average usage is 30%; There's 6 users with a quota 
> increase -one of which is to 4GB.
> If I remember correctly -this is some time ago, before that the environment of 
> 450k users had quota set to 100MB by default. The number of support issues 
> this caused in our little group of 13k users was about 6-10/month. Naturally, 
> such an environment had the means to facilitate delegation properly and such 
> and so forth, so someone in 1st level support could bump the number.
> Like I suggested; maybe I'm not understanding what your workload is like wrt. 
> quota maintenance. Could you share some numbers maybe? Don't get me wrong, I'm 
> merely trying to grasp the problem and get a better understanding of it, and 
> I'm also not arguing against such functionality - I'm trying to get a better 
> understanding so that we can come up with the best solution.

We have about 750 accounts right now.  Quotas vary between 300MB and 20GB.

 - 6 over 10GB
 - 22 over 5GB
 - 78 over 2GB

I recently did a tidy up on them as loads of users were without quotas and
many were set in cyradm and not in ldap (we migrated from kolab v1 not too
long ago and it had some issues with quotas).  Right now, most of our
heavier users are on about 80-85% as I applied new quotas en mass to make
sure everyone's was set somewhat sensibly.

The problem is not really the workload of increasing quotas (though it
would be nice to reduce that).  It's what happens when someone goes over
(or nears) their quota.  They ring the helpdesk expecting to increase the
quota.  The person on the helpdesk who answers the phone has no information
to evaluate whether the increase is justifiable or not.  They can say
"please delete some mail" but that might be unfair on the user who may
already have tried.  They can try and look back through the history to
figure out when that person's last increase was, but that's a pain.  The
result is that the helpdesk person probably just increases the quota
without discussion.  So we quickly end up with meaningless quotas that just
increase as quickly as people consume space.  You can ask the helpdesk
person to be more pushy, but they have no real way to decide who is just
being careless and who simply can't delete any more mail.  The absolute
disk usage isn't really a good guide to this.

If people's quotas increase automatically within reasonable bounds you
should get relatively few people exceeding them.  When someone does call,
it's because they're increasing faster than their allowed rate, which gives
the helpdesk person a much better picture of what's going on.  She knows
how much is in use and that the user is increasing month-on-month faster
than the budget set for them.  It isn't inevitable that they would exceed
their quota so exceeding one's quota is now direct evidence that they're
doing something wrong.

Like you say, this feature can be done external to kolab, it just seemed to
me that this might be quite a useful way to handle quotas in businesses
which accumulate email.


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