Did you try assigning a weight to orange[02-03]? I've found with Slurm it's better to be exact in your slurm.conf and don't relay on the defaults. This is what I use on my cluster:
NodeName=r1n[01-32] weight=10 CoresPerSocket=16 Sockets=2 ThreadsPerCore=1 RealMemory=257000 NodeName=r1n[33-64] weight=20 CoresPerSocket=16 Sockets=2 ThreadsPerCore=1 RealMemory=257000 NodeName=r2n[01-32] weight=10 CoresPerSocket=16 Sockets=2 ThreadsPerCore=1 RealMemory=257000 NodeName=r2n[33-64] weight=20 CoresPerSocket=16 Sockets=2 ThreadsPerCore=1 RealMemory=257000 In my case, we want the nodes towards the bottom (01-32, closer to the cold air flow) to schedule and be used first. The above has worked as expected for us since the system was deployed over 2 years ago.
