From: Herbert Poetzl (herbert_at_13thfloor.at)
Date: Sat 02 Nov 2002 - 00:00:59 GMT
On Fri, Nov 01, 2002 at 10:17:03AM -0700, Mefford, Aaron wrote:
> There was nothing that this page clarified for me. I do already understand
> quotas in general and have used them for some time, albeit not on linux, but
> rather on EMC, NetApp, Sun Solaris and BSD systems. I do not recall any one
> of those systems requiring you to have disk space available equal to the sum
> of all quotas.
>
> I am looking at the Vservers project as a possible solution for offering
> hosted virtual private servers. As part of my requirements, I have some
> specific requirements with regards to disk space management. First I need a
> way to guarantee that no Vserver uses more space than they have purchased,
> without dedicating the same amount of disk to that vserver. Second I need
> the ability to offer this same functionality to the vserver with regards to
> its users, while in some cases requiring that they dedicate space for there
> users and in other cases allowing them to allocate more quota then they have
> purchased from me while still requiring that the vserver as a whole never
> exhausts the space it has purchased from me.
>
> Soft/Hard quotas do not solve this as I understand it, and the link offered
> no additional information in that regard.
soft and hard quota will exactly do what you want, if
and only if, they are for user/group and context,
which was the reason for my development (context quota)
> My understanding is that with vservers as it stands today I can enforce a
> global per user quota, however if I allow the owners of a vserver to create
> additional users, they can then create additional users and get an
> additional grant of space with each additional user they create exceeding
> the desired maximum for that vserver with no way to enforce a maximum disk
> usage, short of using a file based file system or LVM which violates my
> first need of not dedicating the space.
nope, context quota is like user quota, but for the
entire context (all users/groups) so a hard limit of 200M
would mean, that no user within the specified context
(not even the root user) whould be able to write a file
if the context sum reaches 200M
> If I have misunderstood you capabilities please clarify. If this is not
> possible or undesireable for this vserver group then I will simply look
> elsewhere. Anyhow it looks like you have an excellent start on a good
> project.
hope this clarifies it, but I might be wrong, because
I thought it would be simple and well understood in
the first place ...
maybe take a look at http://www.13thfloor.at/VServer/
best,
Herbert
> Cheers,
> Aaron
>
> > -----Original Message-----
> > From: Herbert Poetzl [mailto:herbert_at_13thfloor.at]
> > Sent: Thursday, October 31, 2002 10:43 AM
> > To: vserver_at_solucorp.qc.ca
> > Subject: Re: [vserver] Quotas
> >
> > On Thu, Oct 31, 2002 at 09:08:12AM -0700, Mefford, Aaron wrote:
> > > Soft quotas might suffice, but not really what I am after. Say Joe is a
> > web
> > > developer who has bought a virtual server from me with 500 Mb of space.
> > As
> > > the service provider I want a hard quota that will not allow joe to
> > exceed
> > > 500 Mb, and would typically set a soft quota at 80-90% so that joe gets
> > > upgrade notices prior to running out of disk. Joe has a successful web
> > > development business and has 100 clients whom he has developed sites for
> > and
> > > offers them hosting as well. Knowing these customers will only use 1-10
> > Meg
> > > of actual disk as he designs there sites, yet wanting the customer to
> > feel
> > > comfortable that they are getting there moneys worth (every other
> > provider
> > > is oversubscribing as well and the apparent cost of 100M is 1/10 its
> > actual
> > > value) he gives each site 100M of quota. In doing this he knows that if
> > one
> > > of his clients logs in and fills there quota he will still have disk
> > left,
> > > and have the opportunity to upgrade to compensate after the fact. I
> > monitor
> > > my actual disk usage and by another shelf of disk whenever I reach 75%
> > > usage. I have enough users that even if 10% of them decided to fill
> > disk in
> > > a short period of time, space would still be available.
> >
> > http://www.tldp.org/HOWTO/mini/Quota-5.html
> >
> > best,
> > Herbert