Looking for opinions on my storage set up


I know this isn't strictly speaking network software but it's close enough.

So I'm running out of space on my file server and am in the process of sorting out a new one. Currently I use AUFS on linux to pool all the disks and my current plan is to do the same on the new server and then pool both of them so everything on both servers appears as a single share.

The way I'm planning on doing it is having the pool on the new server shared using samba of NFS, and then mounted on the first server and pooled using AUFS with the other pool already on that server, In this configuration if a client wants a file from the new server that file will have to go to the first server before it goes to the client.

This doesn't seem like a very efficient way of doing it and it's going to create a bit of a bottleneck. Performance isn't really that important but I'm looking for opinions on other ways of setting this up.

So yeah, any ideas would be great.