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I just bought a used HP ProLiant ML350 G4p server and it's power supply gets working immediately after I plug it into power outlet. (the fan is spinning, and the unit consumes 20W of energy) The seller said that this is a normal functionality because of preventing data loss or something. Is it true? This is a feature of this power supply? Can this be turned off? Or this is a failure?

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up vote 8 down vote accepted

This machine (and most server-class computers) have "lights off" management functionality that allows the machine to be managed (to what degree depends on the particular options installed on the machine) even while the machine is "powered off". The power consumption you're seeing is necessary to keep this "lights out" management functionality alive.

I'm not extremely familiar with the HP Compaq server line but I'd doubt that the functionality can be disabled. This type of functionality is one of the reasons why someone would use a server class machine.

If it's bothering you put it on a switchable PDU (power strip, etc) and just turn off the AC when you're not using the box.

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iLO can be disabled. Although I do not know if it would reduce the power consumption. – the-wabbit Nov 23 '11 at 22:47
So this is a normal funtcion. I don't need the lights out function, so i disabled it, but nothing has changed. Thank you so much for your answers! I am smarter now:) – Hiddin Nov 23 '11 at 23:00
@Hiddin, bear in mind that if your server has BBWC (battery backed write cache) functionality on its RAID controller, you'll wear out the batteries pretty quickly by keeping it unpowered, and these batteries are quite expensive too. – fvu Nov 9 '15 at 14:41

It is a server. Meant for running 24/7. Why switching off?

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I bought this machine for an on-demand home server. I don't want it to run 24/7, but it would be nice if i would turn it by a wake-on-lan request. – Hiddin Nov 23 '11 at 22:58

You don't have any means to turn this feature off. There shouldn't be a problem with this, however. The HP ProLiant ML350 G4p has an Integrated Lights-Out (ILO) management controller on the motherboard and the power supplies need to run in order to allow this feature to function.

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This is normal, the power supply still needs to power some embedded system like ILO that would require to cool the power supply.

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Most of the servers i use, HP, Dell, Even if they are shutdown they continue to provide System with some power in order to have controller batteries, temperature control and other parts ready, working and self recycled.

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