[Lustre-discuss] Upgrading our filesystem

[Sebastian Gutierrez]

Hello
So we are currently looking at upgrading one of our Lustre file system.

The current filesystems:
2 MDS servers in a cold spare configuration over IB
2 Filesystems one /home and /scratch
8 OSS with 2 SAS JBODS each has 14x300GB 10K drives.  2 hot spares
2 OSTs per server. One segment is for /home and one for /scratch

Proposed solution by hardware vendor.
8 OSS with 2 SAS JBODS each has 14x600GB 10K drives.  2 hot spares
2OSTs per server.
Both segments would be added onto the /scratch file system.
Max out the memory in the existing OSS systems to plan for future 1.8 
upgrade

I understand the potential administrative overhead in having OSTs that 
are larger than the old OSTs.  I have not been supporting Lustre long 
enough to know if there are any major performance implications of this 
setup.

My questions are:

Will Lustre handle this type of configuration gracefully?
Are there any other reasons that this may not be a good idea other than 
administrative overhead of having to watch the OSTs and make sure that 
they do not fill up?  
Are there any issues with having these new servers serve 2 segments of 
the same filesystem?
Are there anything else I should consider that I may be missing?

Thanks
Sebastian