The issue of what we get on the new ClusterVision cluster is to be discussed today.
I think that SL3 on the grid frontends and the WNs is necessary, but I worry that there might be some nasty driver issue lurking. I'm not sure they've tested SL3 properly.
The nodes which I want to run SL4 on, from the start, are the disk servers. Here we'd like to use xfs for the underlying filesystem, which is safe in 64bits, but dodgy in 32bit x86. It will also spare us the headache of data migration/preservation when the grid middleware finally makes its triumphant leap to SL4.
There are some posts on LCG-ROLLOUT indicating this is possible to so - just need to patch in some of the SL3 RPMs which the 32 bit version of the DPM disk server needs.
Obviously this has to be tested before the machines arrive on the ground - anyone got a time machine?