Re: [gentoo-user] Something like nullfs (FreeBSD) available in linux

[YoYo Siska <yoyo@gl.ksp.sk>]

On Wed, Jan 26, 2011 at 01:37:38PM +0100, Matthias Fechner wrote:
> Dear list,
> 
> I want to build up a NFS share for several host.
> The base system is always equal, only some files are different
> (files in /etc and /var, maybe more).
> 
> The structure should look like:
> Base system is on /basesystem
> 
> Then I want a directory for every host:
> /nfsroot/host1
> /nfsroot/host2
> ..
> /nfsroot/hostn
> 
> Client 1 will boot via lan and mount the /nfsroot/host1 via NFS.
> On the server the mount could look like:
> mount -t nullfs /basesystem /nfsroot/host1
> mount -t nullfs /basesystem /nfsroot/host2
> 
> If the host1 changes now a file the changed file is not stored in
> /basesystem but in /nfsroot/host1.
> (so you can think about a filesystem in two layers, the ground layer
> is /basesystem and readonly, changes will go to /nfsroot/hostn)
> 
> If i upgrade the /basesystem all files should be available for all
> hosts expect the files the host changed by itself (they are stored
> in the nfsroot/hostn directory).
> 
> In FreeBSD there is a file system available called nullfs which
> could be used for this.
> Is there a similar filesystem for Linux available, too?

Unionfs or aufs should be able to do that.

yoyo