Power is required for all our servers, desktops, and other electronic devices to operate.
Power is required for all our servers, desktops, and other electronic devices to operate.
Questions tagged [electrical-power]
431 questions
248
votes
14 answers
What is this very short power cable called?
I have a couple of networking components in my rack that take giant AC adapters ("power bricks") that don't fit neatly into my rackmount PDU.
I have one "thingy" that is shown below, and I need to buy a few more. But I have no idea what I'm…
Portman
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56
votes
6 answers
Why do we still use power supplies on datacenter servers?
Computers mainly need three voltages to work : +12V, +5V and +3,3V, all of them are DC.
Why can't we just have a few (for redundancy) big power supply providing these three voltages to the entire datacenter, and servers directly using it ?
That…
user186340
56
votes
3 answers
Assessing equipment damage following a lightning strike - Should I have planned more?
One of my client's sites received a direct lightning hit last week (coincidentally on Friday the 13th!).
I was remote to the site, but working with someone onsite, I discovered a strange pattern of damage. Both internet links were down, most servers…
ewwhite
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56
votes
14 answers
Is UPS worthwhile for non-production equipment?
Over the years, I've had to throw away a quite a few bits of computing equipment (and the like):
Several ADSL routers with odd symptoms (losing wireless connections, losing wired connections, DHCP failures, DNS symptoms etc)
Two PVRs spontaneously…
Jon Skeet
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52
votes
5 answers
PDU wiring - is this normal (or even safe)?
I removed the side panel of our server rack so I can clean up some of the wiring. Inside I found the PDU was wired like in the picture. Instead of an incoming power cable, there's just 3 uninsulated spade connectors.
Is there any reason for wiring…
Grant
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50
votes
3 answers
ipmitool - can't find /dev/ipmi0 or /dev/ipmidev/0
Based on a previous question, I installed ipmitool (yum install ipmitool).
Even after a reboot, though, i get the following error when trying to run ipmitool power status:
Could not open device at /dev/ipmi0 or /dev/ipmi/0 or /dev/ipmidev/0: No such…
warren
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44
votes
10 answers
Does CPU power management affect server performance?
I was doing some simple hand benchmarking on our (live) database server during non-peak hours, and I noticed that queries returned somewhat erratic benchmark results.
I had enabled the "Balanced" power saving plan on all our servers a while ago,…
Jeff Atwood
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43
votes
6 answers
How do I permanently disable Linux's console screen saver, system-wide?
I've got an Ubuntu server that boots up in text mode. It rarely has a screen or keyboard attached to it, but when I do attach a screen, I usually have to attach a keyboard too, because the darn console mode screen saver will be on and I'll need to…
raldi
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40
votes
3 answers
How do servers with redundant power supplies balance consumption?
I have several servers from the HP DL360 line (generations 5-8). Each of these servers has two power supplies installed. The 2 power supplies in each server are fed from different circuits.
My question is will the power draw be roughly balanced…
Travis Beale
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34
votes
9 answers
UPS and power strip interactions?
Sometimes I hear that you shouldn't plug (UPS brand X / any UPS) into (power strip brand X / any power strip) because of some interaction leading to poorly conditioned power, reduced battery life, massive explosions spattering the room with battery…
chaos
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29
votes
5 answers
How to build and run a machine room?
The last guy quit (I think a lot of adventures begin this way?) and I've been given the job to build a new machine room. I am coordinating with 2 engineers, campus ITS, campus Facilities Management, a project manager, a construction company and 2…
Fixee
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29
votes
2 answers
Disable CPU Scaling in Windows Server 2008 R2
How do you disable CPU power management scaling in Windows Server 2008 R2?
After setting the Control Panel, Power Management plan to performance and then rebooting -- CPUID's Cpu-Z still shows the clock speed being scaled.
Kyle Brandt
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25
votes
6 answers
Best practices for power cabling racks in DC
With network cables it is easy. I use velcro-ties, coloured cables, 0U vertical cable organizers from APC on side of the rack -- easy and neat.
However with power cables it was always giving me headaches.
With some of the racks I am using Vertical…
bart613
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24
votes
4 answers
How to disable all power management in Ubuntu (for a server netbook)?
I need to disable everything related to having the netbook-server go into sleep/hibernate/shutdown. Spinning down the disks during inactivity is fine, but it is crucial that the machine remain in a state where it maintains connectivity over wi-fi…
adewinter
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20
votes
9 answers
VMware ESXi shutdown triggered by APC UPS connected via USB
I am shipping a bunch of ESXi 5.1 servers to remote offices where they will be powered via APC UPS.
I would like to have the UPS trigger a shutdown of the connected server - I would then rely on the ESXi configuration to take care of the…
dunxd
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