[Lustre-discuss] Fwd: Lustre Interoperability Question

[Andreas Dilger]

On 2012-09-19, at 10:38 PM, Ms. Megan Larko wrote:
> I am looking for clarification on a Lustre interoperability question.
> There is a system currently running RHEL 5.5 and Lustre 1.8.3 to
> which new hardware would like to be added.  The new hardware is not
> supported under RHEL 5.x so it needs to be installed as RHEL 6.2 as a
> minimum.   There is considerable doubt that one section of the old
> hardware will be able to function under RHEL 6.   A version of the
> Lustre Manual for 2.0 (
> http://wiki.lustre.org/manual/LustreManual20_HTML/UpgradingLustre.html
> ) Section 16.1 indicates the possibility of heterogenous Luster
> servers---specifically mixed 1.8 and 2.0 servers.  Section 16.1 goes
> on to state that Lustre 1.8.4 must be on the client and server nodes
> not upgraded to 2.0.
> 
> Further research on this issue led me to Whamcloud LU-1116 (
> http://jira.whamcloud.com/browse/LU-1116 ) in which a bug (actually a
> linux kernel item name change) indicates that for a RHEL 6.2 client to
> support 1.8 Lustre (and 2.0 Lustre)  the clients minimum Lustre
> version must be 1.8.7 (patched) or 1.8.8 (where the patch is landed).
> 
> The Question:  Can Lustre effectively serve a file system with
> heterogenous servers of RHEL 5.5 (1.8.3) and RHEL 6.2 (2.1 or better)?
> 
> If not, would a solution of RHEL 5.5 with an upgrade from 1.8.3 to
> 1.8.8 function  with the new hardware using RHEL 6.2 (either Lustre
> 1.8.8 or 2)?   Do the clients have to run Lustre 1.8.8 at a minimum?

Interop rules are:
- servers all need to run the same version of Lustre
- 2.x clients will not work with 1.8 servers
- 1.8.7 clients will work with 2.x servers
- 2.1 clients will work with both RHEL5 and RHEL6

Best would be running 2.1.3 clients and servers everywhere.

Cheers, Andreas
--
Andreas Dilger                       Whamcloud, Inc.
Principal Lustre Engineer            http://www.whamcloud.com/