Configure HP Microserver N54L Power Saving on Debian

HP Microserver N54L power saving and performance tuning using Debian

I’ve installed Open Media Vault on a HP ProLiant MicroServer G7 N54L and use it as media server for the house. OpenMediaVault (OMV) is a network attached storage (NAS) solution based on Debian.

I want to minimise power consumption but maximise performance. Here are some tweaks reduce power consumption and improve network performance.

Power Saving

Install the following.

apt-get install amd64-microcode firmware-linux firmware-linux-free \
firmware-linux-nonfree pciutils powertop radeontool

And for ACPI.

apt-get install acpi acpid acpi-support acpi-support-base


First I enabled PCIE ASPM in the BIOS and forced the kernel to use it and ACPI via grub by changing GRUB_CMDLINE_LINUX_DEFAULT in /etc/default/grub, so it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi=force pcie_aspm=force nmi_watchdog=0"

Then update grub and reboot.


Enable Power Saving via udev

The following rules file /etc/udev/rules.d/90-local-n54l.rules enables power saving modes for all PCI, SCSI and USB devices and ASPM. Futher the internal Radeon card power profile is set to low as there is rarely a monitor connected. The file contains the following:

SUBSYSTEM=="module", KERNEL=="pcie_aspm", ACTION=="add", TEST=="parameters/policy", ATTR{parameters/policy}="powersave"
SUBSYSTEM=="i2c", ACTION=="add", TEST=="power/control", ATTR{power/control}="auto"
SUBSYSTEM=="pci", ACTION=="add", TEST=="power/control", ATTR{power/control}="auto"
SUBSYSTEM=="usb", ACTION=="add", TEST=="power/control", ATTR{power/control}="auto"
SUBSYSTEM=="usb", ACTION=="add", TEST=="power/autosuspend", ATTR{power/autosuspend}="2"
SUBSYSTEM=="scsi", ACTION=="add", TEST=="power/control", ATTR{power/control}="auto"
SUBSYSTEM=="spi", ACTION=="add", TEST=="power/control", ATTR{power/control}="auto"
SUBSYSTEM=="drm", KERNEL=="card*", ACTION=="add", DRIVERS=="radeon", TEST=="power/control", TEST=="device/power_method", ATTR{device/power_method}="profile", ATTR{device/power_profile}="low"
SUBSYSTEM=="scsi_host", KERNEL=="host*", ACTION=="add", TEST=="link_power_management_policy", ATTR{link_power_management_policy}="min_power"

Add this to /erc/rc.local.

echo '1500' > '/proc/sys/vm/dirty_writeback_centisecs'

Hard disk spindown

Using the Open Media Vault web interface got to Storage -> Physical Disks, select each disk in turn and click Edit then set:

  • Advanced Power Management: Intermediate power usage with standby
  • Automatic Acoustic Management: Minimum performance, Minimum acoustic output
  • Spindown time: 20 minutes

Performance Tuning


The following tweaks improve network performance ,but I have a HP NC360T PCI Express Dual Port Gigabit Server Adapter in my N54L so these settings may not be applicable to the onboard NIC.

Add this to /erc/rc.local.

ethtool -G eth0 rx 4096
ethtool -G eth1 rx 4096
ethtool -G eth0 tx 4096
ethtool -G eth1 tx 4096
ifconfig eth0 txqueuelen 1000
ifconfig eth1 txqueuelen 1000

Add the following to /etc/sysctl.d/local.conf.

fs.file-max = 100000
net.core.netdev_max_backlog = 50000
net.core.optmem_max = 40960
net.core.rmem_default = 16777216
net.core.rmem_max = 16777216
net.core.wmem_default = 16777216
net.core.wmem_max = 16777216
net.ipv4.conf.all.accept_redirects = 0
net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.all.send_redirects = 0
net.ipv4.ip_local_port_range = 10000 65000
net.ipv4.tcp_fin_timeout = 10
net.ipv4.tcp_max_syn_backlog = 30000
net.ipv4.tcp_max_tw_buckets = 2000000
net.ipv4.tcp_rfc1337 = 1
net.ipv4.tcp_rmem = 4096 87380 16777216
net.ipv4.tcp_slow_start_after_idle = 0
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_wmem = 4096 65536 16777216
net.ipv4.udp_rmem_min = 8192
net.ipv4.udp_wmem_min = 8192
vm.swappiness = 10


With these settings applied powertop reports everything that can be in a power saving mode is and the room temperature is measurably cooler. More importantly, with four 4TB drives in a RAID-5 configuration formatted with XFS and dual bonded gigabit ethernet, I am able to backup data to the server at a sustained rate of 105MB/s, which is 0.85 Gbit.

Not too shabby for an AMD Turion II Neo N54L (2.2GHz) 🙂