[gpfsug-discuss] Server lost NSD mappings

[Jonathan Buzzard]

On Wed, 2014-10-29 at 15:31 +0000, Jared David Baker wrote:

[SNIP]

> I’m wondering if somebody has seen this type of issue before? Will
> recreating my NSDs destroy the filesystem? I’m thinking that all the
> data is intact, but there is no crucial data on this file system yet,
> so I could recreate the file system, but I would like to learn how to
> solve a problem like this. Thanks for all help and information.
> 

At an educated guess and assuming the disks are visible to the OS (try
dd'ing the first few GB to /dev/null) it looks like you have managed at
some point to wipe the NSD descriptors from the disks - ouch.

The file system will continue to work after this has been done, but if
you start rebooting the NSD servers you will find after the last one has
been restarted the file system is unmountable. Simply unmounting the
file systems from each NDS server is also probably enough. For good
measure unless you have a backup of the NSD descriptors somewhere it is
also an unrecoverable condition.

Lucky for you if there is nothing on it that matters.

My suggestion is re-examine what you did during the firmware upgrade, as
that is the most likely culprit. However bear in mind that it could have
been days or even weeks ago that it occurred.

I would raise a PMR to be sure, but it looks to me like you will be
recreating the file system from scratch.

JAB.

-- 
Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Fife, United Kingdom.