[lustre-discuss] lnet router lustre rpm compatibility

[Mohr Jr, Richard Frank (Rick Mohr)]

> On Jun 20, 2016, at 5:00 PM, Jessica Otey <jotey at nrao.edu> wrote:
> 
> All,
> I am in the process of preparing to upgrade a production lustre system running 1.8.9 to 2.4.3.
> This current system has 2 lnet routers.
> Our plan is to perform the upgrade in 2 stages:
> 1) Upgrade the MDS and OSSes to 2.4.3, leaving clients in 1.8.9.
> 2) Upgrade all clients to 2.4.3 (thus allowing the entire system to be subsequently updated to 2.5 and beyond)
> 
> The problem is that I can't seem to locate any information about the version requirements (if any) for lnet routers. Does the lnet router have to be the same as mds, or the same as the clients? Or both?

The LNet routers do not need to be the same as either the servers or the clients as far as I know.  I don’t know if there is any specific compatibility matrix for LNet versions, but if you are mainly dealing with 1.8.9 and 2.4.3, I think either version would be fine.  With that being said, I usually try to keep my LNet routers and Lustre servers at the same version.  If you are going to take down your servers to upgrade to 2.4.3, you may as well just upgrade the two LNet routers while you are at it.  The clients can then be upgraded later like you listed in your plan.

--
Rick Mohr
Senior HPC System Administrator
National Institute for Computational Sciences
http://www.nics.tennessee.edu