[PATCH 14/18] nfsd: pNFS block layout driver

[J. Bruce Fields]

On Tue, Jan 06, 2015 at 06:39:57PM +0100, Christoph Hellwig wrote:
> On Tue, Jan 06, 2015 at 12:16:58PM -0500, J. Bruce Fields wrote:
> > > +file system must sit on shared storage (typically iSCSI) that is accessible
> > > +to the clients as well as the server.  The file system needs to either sit
> > > +directly on the exported volume, or on a RAID 0 using the MD software RAID
> > > +driver with the version 1 superblock format.  If the filesystem uses sits
> > > +on a RAID 0 device the clients will automatically stripe their I/O over
> > > +multiple LUNs.
> > > +
> > > +On the server pNFS block volume support is automatically if the file system
> > 
> > s/automatically/automatically enabled/.
> > 
> > So there's no server-side configuration required at all?
> 
> The only required configuration is the fencing helper script if you
> want to be able to fence a non-responding client.  For simple test setups
> everything will just work out of the box.

I think we want at a minimum some kind of server-side "off" switch.

If nothing else it'd be handy for troubleshooting.  ("Server crashing?
Could you turn off pnfs blocks and try again?")

--b.