Re: Exporting xfs over nfs

[Stephen Lord <lord@sgi.com>]

Greg Freemyer wrote:

>Eric,
>
>His problems are likely more generic than just XFS / NFS integration.
>
>NFS (on any filesystem) has not historically been very compatible with fail-over clustering  and gives the stale handle message after a fail-over.
>
>As Horms said, there has been a lot of discussion and development related to this recently.
>
>The heartbeat mailing lists archives should cover this topic in detail.  (80+ messages at last count)
>
>FYI: 
>It requires a fair bit of effort, but it can be accomplished.
>
>To my knowledge there is not a out-of-the-box solution, and neither is there a nice clearly written how-to.  
>
>Greg Freemyer
>Internet Engineer
>Deployment and Integration Specialist
>Compaq ASE - Tru64
>Compaq Master ASE - SAN Architect
>The Norcross Group
>www.NorcrossGroup.com
>

First of all, I presume when you fail over to the second node, you 
unmount the xfs filesystem on one
box and mount it on the second one before the IP address takeover 
happens? If not then there is
a good chance of corruption.

That aside, I think that without code changes, the only way to make this 
work is to ensure that the
/dev entry used to mount the filesystem on both boxes has the same 
major/minor number. If not
then I think the stale handles will result. Note this is just a guess on 
my part right now, I have
not looked at this code in a while.

For Irix failsafe I think this has tended to not come up because the two 
nodes are usually an
identical configuration, also the linux nfs client does checking on 
fields of the handle which
other clients do not. Work is now ongoing to add export options to Irix 
NFS to let this
sort of configuration pass in its own device handle to use for nfs clients.

Steve