Coda File System

Re: What happens if the SCM dies?

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Thu, 13 Dec 2001 17:33:49 -0500
On Thu, Dec 13, 2001 at 10:23:40AM -0800, David J. M. Karlsen wrote:
> I'm looking into coda to use it for a cluster of minimum two machines. 
> The replication seems to be fine - so I shouldn't loose any data. But as 
> it's only possible to have one SCM - I wonder what happens if the SCM 
> dies (for good that is - let's say the drives fails due to HW trouble) - 
> will the other non-SCM server with the replica still feed all clients - 
> and all activity goes ahead undisturbed?

If the SCM dies the only thing that is hindered is adding new
users/changing passwords and the creation of new volumes.

It is trivially to select one of the other server as the new SCM. All
required data is already replicated, you just need to tell every server
who the new SCM is
    ( echo 'newscmhostname' > /vice/db/scm ;
      /etc/rc.d/init.d/update.init restart )

Regular Coda clients accessing the system are not disturbed at all.

Jan
Received on 2001-12-13 17:34:01