[Samba] SAMBA Cluster or .......

[Jeremy Allison]

On Fri, Mar 09, 2007 at 11:45:50AM +0100, Marcin Giedz wrote:
> Hello,
> 
> My question is quite related to this topic. Currently I work for one of 
> brokerages and prepare to set up domain for all employees. However I 
> must be sure that if my PDC fails my BDC will provide all connections to 
> roaming profiles and extra shares (to be mounted during the log in 
> process). But additionally I want to have only ONE storage place for 
> placing every shares and profiles. Lucky, I "found" one EMC disk array 
> to be used in this solution. My idea is connect 2 server (PDC and BDC) 
> over FCs to ONE storage. I don't have any extra software like "cluster 
> solution".
> 
> Now I have almost everything UP and running but found this "thread" 
> about "data consistency" where different Samba instances may cause data 
> corruption.
> "....
> 
> Please NEVER export the same file space via different Samba
> nodes, this leads to data corruption because the locks
> propagated have the wrong semantics...."
> 
> Now I'm wondering if I can really do this? According to what Volker said 
> my solution/idea is (in a word) - BROKEN :(
> Does this me that I must use some extra software between EMC storage and 
> Samba instances to prevent data lost? In my situation there is a  chance 
> that PDC and BDC will server THE SAME file for different users.
> 
> So looking at this topic I'd come to think that I CAN'T go production 
> with such prepared PDC + BDC + EMC storage - am I right? If yes would 
> anyone propose any solution for such idea?

You have to be careful to do this. It's safe to do for
a failover solution (no 2 Samba servers active at the
same time), it's also safe for read-only shares.

If you have active processes writing data simultaneously
to the same file then they should be pointing at the
same Samba server.

Jeremy.