Gluster users - Apr 2013 - A simple way to federate gluster namespace ?

Hi guys:

BTW thanks for the insights regarding locality .  Now I have a new stupid
question for you:

Namespace federation !

Say I have two gluster volumes, and I want to access both volumes from the
same mount point.

It would be cool if there was a "gluster volume federate volA volB
supervol", which created a new volume that read/wrote to supervol/volA
super/volB transparently.

But in the absence of such a command, could I just federate two gluster
namespaces using the mount command? Would there be nasty hidden overhead
and costs to this?

i.e. something like:

mount -o /tmp/supermount/subA /submount/a
mount -o /tmp/supermount/subB /submount/b

Or maybe you could do the equivalent with symlinks?


-- 
Jay Vyas
http://jayunit100.blogspot.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://supercolony.gluster.org/pipermail/gluster-users/attachments/20130405/cbb34c6d/attachment.html>

On 04/05/13 15:33, Jay Vyas wrote:
> Hi guys:
>
> BTW thanks for the insights regarding locality .  Now I have a new
> stupid question for you:
>
> Namespace federation !
>
> Say I have two gluster volumes, and I want to access both volumes from
> the same mount point.
>
> It would be cool if there was a "gluster volume federate volA volB
> supervol", which created a new volume that read/wrote to supervol/volA
> super/volB transparently.
>
> But in the absence of such a command, could I just federate two gluster
> namespaces using the mount command? Would there be nasty hidden overhead
> and costs to this?
>
> i.e. something like:
>
> mount -o /tmp/supermount/subA /submount/a
> mount -o /tmp/supermount/subB /submount/b
>
> Or maybe you could do the equivalent with symlinks?
Are you wanting to mix namespaces or make a tree?

A tree is easy:
/mnt/vola
/mnt/volb

If you want to mix namespaces (i.e. have the roots mingle so an ls show 
files from both), that is not possible.

In linux you might be able to hack something with unionfs, but I am not 
sure.

You won't be able to have a server mount both, then us them as bricks in 
a "super volume", as the xattrs will clash.

-- 
Mr. Flibble
King of the Potato People