[Gluster-users] server side afr, workstation unify?

[Wolfgang Pauli]

Hi,

Hm ... I think I understood your email and we are on the same page. However, 
it seems like an afr of a unify volume and a posix volume don't work. 

Files created in the unify volume never show up in the mounted afr volume. If 
I create a file in the afr volume, that works, but is followed by 
Input/Output errors, until I do a setfattr -x trusted.glusterfs.version on 
the directories. (Can give a more detailed description in case this looks 
like a bug)

Is it possible that a afr over a unify is just not supposed to work?

Thanks!

Wolfgang

On Tuesday 05 August 2008 20:56:10 Keith Freedman wrote:
> ok.  I see what you're trying to do.
> I belive the afr of the unify in the 2nd another node should be fine.
>
> I'm guessing what you're experiencing is that dream-mirror is empty?
>
> for the AFR brick, I'd add a local read volume as your unify, unless
> you want anothernode2 to read from the mirror, which I think you don't.
>
> Is something mounting afr0?   As I understand it, the afr happens
> when files are accessed through the AFR volume.
> So, just defining the volume doesn't accomplish anything.
> When you access a file that's mounted on the afr volume (or on a
> volume below the afr volume), the AFR translator, asks both bricks
> for the extended attributes and the file timestamp (and for the
> directory as well).   If they're not the same, then it copies over
> the new one to the mirror(s).  However, if no file request ever
> passes through the AFR translator, then nothing gets replicated.
>
> So, some node has to moun the AFR brick.
>
> your configuration is actually a good one for doing periodic mirroring.
> you mount the afr volume, run a find (there are examples in the wiki)
> across the new mount point, thus causing auto-healing of the entire
> volume. then unmount it.
> And you have effectively a point in time snapshot.
>
> You then mount it again, run find to auto-heal.
>
> However, if you want "live" replication, then you need the AFR volume
> to be in use and active..
>
> Ideally, you should have ALL the nodes using the AFR config, and
> mounting the AFR volume --- set the unify brick as the read volume.
>
> This way, anytime any node reads data, it reads from the unify and
> anytime any of them write data, it gets written to the mirro via the
> AFR translator.
>
> I hope I understood your intentions clearly.
>
> Keith
>
> At 04:09 PM 8/5/2008, Wolfgang Pauli wrote:
> >Hi,
> >
> >Thanks for you your reply.
> >
> >Here is the part of my configuration file that might explain better what I
> > am trying to do.
> >
> >-----------
> >#glusterfs-server-dream.vol
> >
> ># dream-mirror is the directory where I would like to have a complete copy
> > of unify0
> >volume dream-mirror
> >    type storage/posix
> >    option directory /glusterfs-mirror
> >end-volume
> >
> >volume dream
> >    type storage/posix
> >    option directory /glusterfs
> >end-volume
> >
> ># namespace for unify0
> >volume dream-ns
> >    type storage/posix
> >    option directory /glusterfs-ns
> >end-volume
> >
> ># another node
> >volume neo
> >    type protocol/client
> >    option transport-type tcp/client
> >    option remote-host neo # defined in /etc/hosts
> >    option remote-subvolume neo
> >end-volume
> >
> >#another node
> >volume echo
> >    type protocol/client
> >    option transport-type tcp/client
> >    option remote-host echo
> >    option remote-subvolume echo
> >end-volume
> >
> >volume unify0
> >   type cluster/unify
> >   option scheduler rr # round robin # going to switch to NUFA
> >   option namespace dream-ns
> >   subvolumes dream echo neo
> >end-volume
> >
> >volume afr0
> >   type cluster/afr
> >   subvolumes unify0 dream-mirror
> >end-volume
> >
> >volume server
> >    type protocol/server
> >    option transport-type tcp/server
> >    subvolumes dream dream-ns unify0
> >    option auth.ip.dream.allow *
> >    option auth.ip.dream-ns.allow *
> >    option auth.ip.unify0.allow *
> >#   option auth.ip.dream-mirror.allow *
> >#   option auth.ip.afr0.allow *
> >end-volume
> >
> >----------
> >
> ># glusterfs-client-dream.vol
> >
> >volume unify0
> >    type protocol/client
> >    option transport-type tcp/client
> >    option remote-host 127.0.0.1   # IP address of server2
> >    option remote-subvolume unify0   # use dream on server2
> >end-volume
> >
> >----------------
> >
> >the problem with our network is that it is slow (100MBit/s). So it would
> > be great if all files (talking about /home/*) would just stay on the
> > workstations, unless needed somewhere else. So I would like to do a afr
> > over a unify guy, but so far volume dream-mirror remains empty.
> >
> >Thanks!
> >
> >Wolfgang
> >
> >
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