Scouting the Internet on information about the new G6 evolution of HP servers I ran into a valuable article from Martijn Lohmeijer’s blog.

In a lessons learned article he warns about the new memory management in the new HP ProLiant DL360/380 G6.

We all know what happens when new hardware is delivered (at least I do). Techies as we are, we start unpacking the servers, flip the cover and inspect the new Intel Nehalem CPUs, fiber channel HBAs and SSDs murmuring about GHzs, GB, IOPS and FSBs with some additional ‘oh’, ‘ah’ and ‘cools’. Then put in the memory, disks and other toys we ordered and rush it to the server room or test area, plug it in, install an operating system or hypervisor. We then find out that the server is not performing as expected and start screwing up BIOS settings and pulling out components.

All you should have done after unpacking your new present is reading the manual and the quick specs of the server (which we (as techies (and men) never do).

The following is a enumeration of the most important items from the quick specs of the HP ProLiant DL360 G6.

DDR3 memory population guidelines Some DIMM installation guidelines are summarized below:
  • DIMM slots that are white should be populated first
  • Do not mix Unbuffered memory (UDIMMs) with Registered memory (RDIMMs)
  • If only one processor is installed in a 2CPU system, only half of the DIMM slots are available
  • Do not install DIMMs if the corresponding processor is not installed
  • To maximize performance, balance the total memory capacity between all installed processors
  • You can only install two quad-rank DIMMs per channel
  • You can only install two UDIMMs per channel; if available, the third slot in the channel must remain empty

A full list can be found in Martijn’s article or on the HP website.