[Gluster-devel] Re: AFR + unify + namespace question

[Brandon Lamb]

On Sat, May 3, 2008 at 3:26 PM, Brandon Lamb <brandonlamb at gmail.com> wrote:
> On Sat, May 3, 2008 at 2:56 PM, Brandon Lamb <brandonlamb at gmail.com> wrote:
> >
> > On Sat, May 3, 2008 at 2:50 PM, Brandon Lamb <brandonlamb at gmail.com> wrote:
> > > I couldnt find anything related to this with a quick search.
> > >
> > > Lets take a case where we have 3 data servers, so we do AFR using
> > > unify. For unify we specify a namespace volume that exists on lets say
> > > server1.
> > >
> > > Ok so what happens when server1 goes down, now there is no namespace.
> > > What are the implications and is there a common solution to avoid
> > > this?
> >
> > http://gluster.org/docs/index.php/Aggregating_Three_Storage_Servers_with_Unify
> >
> > Ok so I started to attempt to create a 3 server 2 client setup. I
> > thought I would use 3 servers and i would only want 2 copies of files.
> > I thought to do this you needed afr + unify.
> >
> > However, AFR uses the number of servers as the number of copies, so
> > even using 3 servers I dont see a reason to use unify? Wont it just
> > send every write to all 3 servers anyway? So what is unify doing in
> > the example?
> >
> > Is that just a bad example that I am trying to follow?
>
> http://gluster.org/docs/index.php/Understanding_Unify_Translator
>
> I just finished reading the very bottom of this page. So what I got
> from that page is that if the server which holds the namespace goes
> down, something bad will happen?
>
> So what is the "recommended" solution for this? Have a seperate
> machine that does nothing export only a name space directory? At least
> until 1.4 and having the addition of distributed namespace?

http://www.gluster.org/docs/index.php/Unify_over_AFR

Ok wow either im totally blind or this was just added recently?
EXACTLY what I was looking for minus any explanation or details about
it, but I understand what it is doing. Very cool! afr the namespace
duh.