NFS server redundancy/failover

[Chuck Swiger]

Guy Van Sanden wrote:
[ ... ]
> Does anyone know if and how it is possible to set up a redundant NFS server?

Yes, although true redundancy for NFS is available only for read-only shares. 
 From "man mount_nfs" under Solaris:

      Replicated file systems and failover
            resource can list multiple read-only file  systems  to
            be  used  to  provide  data. These file systems should
            contain equivalent directory structures and  identical
            files.  It is also recommended that they be created by
            a utility such as rdist(1). The file  systems  may  be
            specified   either  with  a  comma-separated  list  of
            host:/pathname entries and/or NFS URL entries, or with
            a  comma -separated list of hosts,  if all file system
            names are the same. If multiple file systems are named
            and  the  first  server  in the list is down, failover
            will use the next alternate server  to  access  files.
            If  the  read-only  option  is not chosen, replication
            will be disabled. File access  will block on the  ori-
            ginal if  NFS locks are active for that file.

> What I want to do is this, I have a primary NFS server that serves home directories and data storage.
> I also have a second system with a lot of disk-capacity, I could set it up as a 'mirror' using rsync.
> Now, when the primary NFS goes down, clients should automaticly look for the backup one.

If the data is read-write, and you need fileserver redundancy, NFS is not 
adequate: you should consider AFS/DFS instead, although I've heard rumors that 
the OpenAFS (Arla?) software is somewhat broken on FreeBSD at this point.

-- 
-Chuck