[Gluster-devel] AFR comments. Maximizing free space use when using mirroring

[Krishna Srinivas]

On 8/1/07, DeeDee Park <deedee6905 at hotmail.com> wrote:
> > >
> > > The idea I have is that I want to use as many available commodity parts
> >that
> > > I can find and
> > > build a largest file server for my customer's needs and reallocating the
> > > remaining space for
> > > replicas. I still have a lot of these 120GB drives sitting around from a
> >few
> > > years ago, and I've
> > > got 500/750GB drives. It seems to be a difficult task to match each
> >120GB
> > > drive with another
> > > 120GB drive to optimize disk usage for AFR purposes. I could have 2
> >500GB
> > > drives for
> > > replication *:2, but if I want to move to *:3 in the future, most likely
> > > I'll have some 750GB
> > > drives laying around. Using a 750GB as my third brick would most likely
> > > waste the remaining 250GB.
> >
> >You can just put the bigger drive brick as the first subvolume in the
> >subvolume
> >list. This should fix the problem right?
>
> Yes, it would give the user more space, but wouldn't there be some kind of
> error
> message when the replica disk runs out of space once the primary 750GB
> contains
> more than 250GB of data? Once the user exceeds 250GB, then they no longer
> have a replica (false sense of security... bad).
>

That would be disk space management issue which the admin should
take care of and AFR should not worry about. When we come up with a
web management interface the admin should automatically know what disks
have reached critical stage. For now though he should manually monitor
the disk space.

Regards
Krishna