Last year I could successfully build a low power but high performance NAS based on Haswell and Openmediavault Kralizec running below 12 watts (idle) with 3 x 4TB disks Raid5 installed.
http://forums.openmediavault.o…nce-Haswell-based-OMV-NAS
One of the disadvantages with this config is that the used Intel DH87RL motherboard does not support ECC memory, which is e.g. beneficial to run ZFS. Comparable server configurations during this time were much above in the range of 20 watts idle /wo disks.
Now since the availability of Skylake CPUs as well as the ZFS plugin in Openmediavault, I was wondering when new low power server boards will become available. Ct magazine 5/16 published a first test with several skylake server boards featuring ECC RAM. Power /wo disks was mentioned to be as low as 9 watts for the Fujitsu D3417-B.
So my decision was to give it a try to achieve again below 15 watts idle power on an Openmediavault NAS with 3 x 4TD disks, but this time with ECC and ZFS. The focus here is again on low power idle and not so much on the ZFS config and performance.
Hardware
- CPU Intel Pentium G3900 2.8 GHz (with boxed cooler)
- Mainboard Fujitsu D3417-B
- ECC RAM 2 x Samsung DDR4 8GB DIMM 288-PIN 2133 MHz / PC4-17000 M391A1G43DB0-CPB ECC
- Case Corsair Carbide 200R (need to exchange the fans as the D3417 only supports PWM fans)
- PSU Be quiet pure power 300 Watt L8
- SSD Samsung SM951 NVMe 128GB M.2
- Disks 3 x WD Red 4 TB
Since Skylake CPUs are only supported well in kernels 4.3+ I decided to do some testing (NO productive setup) on OMV 3.x Erasmus.
To get it working I had to manually install Debian Jessie instead of the OMV 3.0.2 image, to work around a grub bug that prevents from install grub on the M.2 SSD. Jessie comes with 3.16 kernel and 4.3 is available as backport.
http://www.poweredbyjeff.com/2…750-SSD-in-Debian-Jessie/
(had to change line 2: mount –-rbind /proc proc/ )
Then there was an issue with the backport kernel that the intel i915 firmware was missing.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800835
The specific firmware is part of the firmware-misc-nonfree package (justinstall it and the error will go away).
The OMV Erasmus install on Jessie was straight forward. Powertop was used to do power optimization but I expect some kernel issues are still to be solved in upcoming backports.
Power figures are measured at the AC side 230V /w KD 302
35 watts - SMB large file copy to/from OMV NAS maxing out GiB speed
30 watts - incremental file access/backup
26 watts - OMV idle / 3x4TB disks spinning
14 watts - OMV idle/ 3x4TB disks spun down
The power consumption measured in this setup (still non-optimized) is already very good although it shows slightly higher power consumption in idle modes compared with my optimized Haswell build.
More fine tuning will NOT be performed before next kernel backports 4.4+ and official Erasmus releases will become available as several issues are pending to be resolved.
update June 2016:
With backport Kernel 4.6.x still no change in power savings. Fujitsu indicated in their technote update 1.4 June/2016 that NVMe support will be improved Q3/2016. Up to now ASPM cannot be properly used with the Samsung NVMe SSD. Will update the power figures once the new BIOS is available.