33 votes
Accepted

Can Running a Server's Redundant PSU on Different Circuits Damage It?

With multi-phase AC systems (motors, etc.), you're right, bad things can and will happen if one of the phases drops out. However, with computer PSUs, each of them operates completely separately, ...
EEAA's user avatar
  • 110k
33 votes
Accepted

Is it safe to use a UPS designed for desktop PCs to power a server?

I would not plug a server with a power supply capable of drawing 750 watts into a UPS which is only rated at 240. The issue isn't really that it's a "server" or "desktop" UPS. You're likely to ...
USD Matt's user avatar
  • 5,411
26 votes

Plugging in a server rack with UPSes into a room that has its own UPS backup issues

Your typical UPS (i.e., excluding a double-conversion UPS), including all APC SmartUPS that I've worked with in the past, does nothing to the power except when running on batteries. It will draw a ...
manassehkatz-Moving 2 Codidact's user avatar
23 votes

Plugging in a server rack with UPSes into a room that has its own UPS backup issues

Every data center/server room I've ever been in and worked in, that had its own UPS system, has prohibited customers, clients, etc. from using their own UPS systems. I can't speak to power harmonics, ...
joeqwerty's user avatar
  • 111k
22 votes

How to disable all power management in Ubuntu (for a server netbook)?

On Ubuntu 16.04 LTS, I successfully used the following to disable suspend: sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target And this to re-enable it: sudo ...
Dustin Kirkland's user avatar
21 votes
Accepted

Dual power supplies on the same circuit

No, not really. This is a perfectly good way to protect against a power supply failing, as long as it doesn't fail in such a way as to draw massive amounts of current (very unusual). Normally people ...
Falcon Momot's user avatar
  • 25.3k
18 votes
Accepted

Is there a way to protect SSD from corruption due to power loss?

When suddenly losing power, MLC/TLC/QLC SSDs have two failure modes: they lose the in-flight and in-DRAM-only writes; they can corrupt any data-at-rest stored in the lower page of the NAND cell being ...
shodanshok's user avatar
  • 50.3k
17 votes

Is it safe to use a UPS designed for desktop PCs to power a server?

Your UPS provides power when the utility mains drops, and protects from transient under and over voltage/current conditions. Given you can plug a desktop or a server or a UPS into the same supply ...
Criggie's user avatar
  • 2,321
11 votes

Is there a way to protect SSD from corruption due to power loss?

Yeah. Don't get super cheap SSD - anything outside the low end consumer market has capacitators and full protection against power loss. Amd really does not cost that much more.
TomTom's user avatar
  • 51.9k
8 votes

How do I move a server to a new power source without powering it off?

Just schedule downtime and turn the server off. Without a dual power supply setup, you don't have any other reasonable options. If there are business constraints or otherwise, you should note those ...
ewwhite's user avatar
  • 198k
8 votes

Plugging in a server rack with UPSes into a room that has its own UPS backup issues

Fire safety. The datacenter operators should be able to kill the power to the room, should an emergency happen. Your UPS units are outside of their control. Batteries themselves are dangerous. A ...
fraxinus's user avatar
  • 624
7 votes
Accepted

Can you exceed power rating on a UPS with additional battery packs

The Wattage and VA rating of the UPS represents the load that the UPS can protect. The battery and expansion packs only exist to increase the runtime of the UPS. I would suggest multiple 2200VA UPS ...
ewwhite's user avatar
  • 198k
7 votes
Accepted

Is it possible to convert 4-pin floppy to SATA power?

Yes, it is legit. All of these adapters use +5V or +12V pins with some earthing. The adapter what you want to buy does only the physical conversion, because no electrical conversion is needed. You ...
peterh's user avatar
  • 4,971
7 votes

Is there a way to protect SSD from corruption due to power loss?

The first thing to do is to define recovery time and recovery point objectives. How long do you have to recover one of these terminals, and what data point in time is acceptable? Perhaps within a ...
John Mahowald's user avatar
6 votes

Can Running a Server's Redundant PSU on Different Circuits Damage It?

The job of the power supply is to take power that is not 100% clean and make is stable. People working in data centers have been fired for not having the power supplies run on different circuits. If ...
Super1337's user avatar
  • 474
6 votes

Is it safe to use a UPS designed for desktop PCs to power a server?

Back-UPS is not suitable for server protection. More or less suitable is the smart-UPS that has a way more sophisticated controller inside. The typical operation cycle for a power supply when the wall ...
Kondybas's user avatar
  • 7,014
6 votes
Accepted

Redundant UPS with 2 power sources

You're looking for a power distribution unit (PDU) with an automatic transfer switch (ATS). The PDU can choose a power source from two (or more) sources to use -- in this case, it would use one with ...
lungj's user avatar
  • 296
6 votes
Accepted

Why do servers have 2 PSU?

You have two power supplies for redundancy. Assuming they are hot-plug, if one fails you can replace it while the system is still running. You could also run to separate servers in your data center ...
Zoredache's user avatar
  • 132k
6 votes

Plugging in a server rack with UPSes into a room that has its own UPS backup issues

Aside from the practical problems, most UPS manufacturers, including APC advise you not to do it and it will void your warranty. Additionally, using equipment not as designed may violate local ...
richardb's user avatar
  • 1,256
5 votes

UPS Requirements - Max load or actual load?

Measure the real utilization of your systems infrastructure at present and build in room for expansion, spikes in utilization and normal growth. There's nothing more than that. As for UPS design, it ...
ewwhite's user avatar
  • 198k
5 votes

ipmitool - can't find /dev/ipmi0 or /dev/ipmidev/0

Just wanted to highlight another minor point: "Make sure you are running with root/admin privileges". user@host:~$ ipmitool power status Could not open device at /dev/ipmi0 or /dev/ipmi/0 or ...
sid's user avatar
  • 51
5 votes
Accepted

Reduce the risk of data corruption due to power loss

Storage controllers can come with a Battery Backed Write Cache and/or a super cap(icitor) in the case of SSD's to protect cached writes during power outages. There are indeed scenario's when those ...
HBruijn's user avatar
  • 79.9k
4 votes

HP ProCurve 5412zl warm-boots on power failure while attached to UPS

According to this page, your UPS series is of the "line interactive" type. This designation means that it isn't constantly converting the utility power to DC and back to mains level again. Rather, it'...
Mels's user avatar
  • 685
4 votes

How to wake a server after UPS Shuts it down when Mains power is restored?

After reading many suggestions, I think that a good solution is to use any old computer (if you don't care about power consumption), or some kind of raspberry pi, connected direct to energy. So, ...
Job Diógenes Ribeiro Borges's user avatar
4 votes

What is the lifespan of an typical UPS battery?

APC says 3-5 years: http://www.apc.com/solutions/display.cfm?id=1371A38E-2B31-B5C1-CADC3E466F676960&ISOCountryCode=us Also here: http://www.schneider-electric.us/en/faqs/FA158934/ The above is ...
Jonesome Reinstate Monica's user avatar
4 votes

Cannot boot server after power failure

After rapidly switch on off the psu in furious rage, the server finally boots.
Syaiful Nizam Yahya's user avatar
4 votes

How to gracefully shut a computer down with a wall mounted light switch

Even a basic communication cable between the computer and the UPS should include a way to signal the UPS to power off the inverter, usually with some delay. That signal might only work when incoming ...
telcoM's user avatar
  • 4,568
4 votes

Did HP ever advise splitting receptacles for redundant power?

I've worked with HP gear for 25 years and I seriously doubt that. It would be gross negligence. The following is consistent with other HP rack documentation I have read in the past: https://assets.ext....
Greg Askew's user avatar
  • 36.6k
3 votes

ProLiant DL380 G7 won't boot, solid amber power LED

If all of the above did not help, like it was for me, unplug all PSUs, remove CMOS battery and check its voltage level. If it is below 2.9V when removed - trash it and get a new one. After being hit ...
Peter Zhabin's user avatar
  • 2,871
3 votes
Accepted

Daily Cost to run Dell Power Edge R900 and HP DL580 G5

Long answer and details First of all, power cost usually goes in energy units of kW*h (not kW), e.g. $N if you consume 1kW for 1 hour. Then you pay $24N for 1 day. I guess you pay $0.11 per every kW ...
aaaaa says reinstate Monica's user avatar

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