Freenas Power Management: Waking And Sleeping Your Server

FreeNAS is a server software that is not designed to be turned off or put to sleep. However, some users have found ways to work around this. One method is to enable SSH access and execute specific commands to shut down and wake up the server. Another method is to use Wake-on-LAN (WoL) by ensuring that the BIOS supports WoL and that the operating system driver supports it. Additionally, some users have suggested modifying settings on the drives and getting the system dataset off the data pool. While these workarounds exist, it is important to consider the potential wear and tear on the drives and the relatively minor power savings.

FreeNAS is now TrueNAS

However, there are some things you can try to save power, such as modifying settings on the drives and getting the system dataset off your data pool. You can also try going to Services -> S.M.A.R.T and setting the power mode to "stand by", so SMART doesn't wake up the disks. If you enable SSH access to your FreeNAS, you can execute:

Plink -ssh -pw [PASSWORD] [root]@[IP OF FREENAS] shutdown -p now

Where PASSWORD is the password of the FreeNAS root user and IP OF FREENAS is the IP address of your FreeNAS. To wake up FreeNAS, you can use a tool called wol.exe. If you use wol.exe followed by the MAC address of your network card, it sends a wake-on-LAN package. Both commands can be scripted and scheduled by the Windows Task Scheduler.

You can also try Wake on LAN (WoL) by going to the BIOS of your server, making sure it is turned on, and then pressing the power-off button. The server should power off and it should also now allow you to do WoL because the power-off was done by the BIOS, not by the operating system.

FreeNAS is not built to go to sleep

Some users have tried to get FreeNAS to sleep by enabling SSH access and then executing specific commands, but this does not always work. Others have tried to use Wake-on-LAN (WoL) by going into the BIOS of their server and ensuring that WoL is turned on before pressing the power-off button. However, this also depends on the operating system and other hardware components.

If you are looking to save power, there are other ways to do so without putting your FreeNAS server to sleep. For example, you can set it to wake up every night at the same time for about 6 hours, which is enough to run backup jobs and scrubs. Alternatively, you can try to spin down your idle hard drives to standby mode by going to Services -> S.M.A.R.T and setting the power mode to "stand by".

Wake on LAN (WoL)

Wake-on-LAN (WoL) is a computer networking standard that allows devices to be turned on or awakened from sleep mode by a network message. The message is usually sent to the target computer by a program executed on a device connected to the same local area network (LAN). It is also possible to initiate the message from another network by using subnet-directed broadcasts or a WoL gateway service.

WoL is implemented using a specially designed frame called a "magic packet", which is commonly sent to all computers in a network, including the computer to be awakened. The magic packet contains the MAC address of the destination computer. This is an identifying number built into each network interface controller (NIC) that enables the NIC to be uniquely recognised and addressed on a network. In computers capable of Wake-on-LAN, the NICs listen to incoming packets, even when the rest of the system is powered down. If a magic packet arrives and is addressed to the device's MAC address, the NIC signals the computer's power supply or motherboard to awaken. This has the same effect as pressing the power button.

Wake-on-LAN can be a difficult technology to implement because it requires appropriate BIOS/UEFI, network interface hardware, and sometimes operating system configuration. It is based on AMD's Magic Packet Technology, which was co-developed by AMD and Hewlett-Packard, following its proposal as a standard in 1995. The standard saw quick adoption thereafter through IBM, Intel, and others.

To enable Wake-on-LAN on your devices, your computer should be connected to an ATX-compatible power supply, which has an extra +3.3V voltage rail. A voltage rail gives a device the ability to switch between alternating current and direct current power. To enable direct broadcast in routers, an access control list (ACL) has to be created and added to all the routers within the network. The ACL is a set of rules designed for monitoring incoming and outgoing network traffic. The network interface card must be Wake-on-LAN-enabled.

ACPI and acpiconf

ACPI (Advanced Configuration and Power Interface) is a power management specification that allows the operating system to control the power usage of its components. It is an industry standard for power management and is supported by many operating systems, including FreeNAS.

Acpiconf is a utility that allows the user to control the ACPI power management functions. It was written by Mitsuru Iwasaki and first appeared in FreeBSD 5.0. The utility allows the user to enter a specified sleep mode, get design information about the battery, and abort a pending suspend request. The recognised sleep modes are:

• Cm 1 (only the CPU clock is stopped)
• Cm 2 (not implemented on most systems but similar to S1)
• Cm 3 (the CPU context is lost and memory context is preserved)
• Cm 4 (the CPU context is lost and memory context is stored to disk)
• Cm 5 (soft off)

The supported sleep states depend on the BIOS implementation, including ACPI byte code (AML). If the /etc/rc.suspend and /etc/rc.resume scripts are executable, they will be run before and after entering the given sleep state.

In the context of FreeNAS, some users have expressed interest in putting their FreeNAS server to sleep when not in use to save power. While server software is not typically designed to be used like this, and there is no official sleep mode, some users have found workarounds using acpiconf and other tools. One user shared a script that checks the activity of specified IP addresses and shuts down FreeNAS if they are inactive. To wake up the server, a "wake on LAN" command or a "magic packet" can be used.

HDD standby mode

FreeNAS does not have a sleep mode as it is meant to be available to perform tasks at all times. However, you can set up a cron job to shut down FreeNAS when it is not in use and wake it up when it is needed.

To put your hard drives in standby mode, you can use the command "ataidle -s /dev/ada0". This will force them into standby until they are accessed. You can also set a timer for the standby mode, choosing between 120 to 300 minutes so that the drives don't sleep during the day but can spin down at night. Additionally, you can set "HDD Standby" to "Always On" under Storage > View Disks > Edit.

Another way to save power is to move the System Dataset off the disks that are constantly logging. This can be done under System > Preferences. You can also move your boot to a USB hard disk to avoid wearing out your USB Sticks and SD Cards.

Frequently asked questions