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The New "d820" Nodes

The New "d820" Nodes

Machines and Interfaces

16 d820 PC nodes (pc601-pc616) consisting of:

  • Dell r820 2U servers
  • Four 2.2 GHz 64-bit 8-Core E5-4620 "Sandy Bridge" processors, 7.20 GT/s bus speed, 16 MB cache, and VT (VT-x, EPT, and VT-d) support
  • 128 GB 1333 MHz DDR3 RAM (8 x 16GB modules)
  • 4 Broadcom NetXtreme BCM5720C GbE NICs builtin to motherboard (only one in use)
  • 2 dual-port Intel X520 PRO/10GbE PCI-Express NICs
  • 250GB 7200 rpm SATA disk, 6 x 600GB 10000 rpm SAS disks

Switch Configuration

The experiment backplane consists of four 10Gb interfaces connected to an Arista 7504 switch.

Important: The interfaces in the d820 nodes are not capable of operating at speeds lower than 10Gb, so make sure to request link speeds of "10Gb" or "*" in your NS file.

Images and Kernel Support

Currently, the following Emulab standard images are supported on these machines:

  • Ubuntu14:
    • 64-bit: UBUNTU14-64-STD
  • CentOS:
    • 64-bit: CENTOS71-64-STD
  • FreeBSD:
    • 64-bit: FBSD102-64-STD
  • Xen 4.4 with Ubuntu14 "dom0":
    • 64-bit: XEN44-64-STD

Many of the other standard Emulab images will likely work as well, though older FreeBSD and Fedora images will not work.


  • No support for 32-bit OS images. No technical reason here, just low priority. 32-bit OSes would allow access to only 4GB of the 128GB of RAM, so there is no good reason to use them.
  • Limited configuration of local storage. Each of the nodes has six 600GB hard drives in addition to the 250GB system disk. While these drives are connected to a hardware RAID controller, we have them configured as "non-RAID" in the BIOS for the time being. You will need to use a software RAID solution (e.g., LVM or ZFS) if you want very large or very fast local storage. We suggest you look at Emulab Blockstores as a way of configuring the extra disk space.