101 votes
Accepted

Smell of rotten eggs in the server room

To answer the question: This is almost always a lead-acid battery failure causing the battery to vent hydrogen sulfide (H2S). The battery needs to be replaced as soon as possible. As an additional ...
bwDraco's user avatar
  • 1,644
80 votes
Accepted

What are the pros and cons of having your own UPS attached to your own server hosted in a data center?

Pros: None Cons: It interrupts the flow of the Emergency Power Off (EPO) in the datacenter. If there is a life or death emergency in a datacenter, that EPO might be triggered to save someone's life....
Mark Henderson's user avatar
56 votes

Smell of rotten eggs in the server room

It sounds like one of your lead-acid batteries has gone bad and is now leaking hydrogen sulfide (H2S) into the air. You will obviously want to replace the battery, but I would think some cleaning may ...
Håkan Lindqvist's user avatar
39 votes

What are the pros and cons of having your own UPS attached to your own server hosted in a data center?

Apart from low-probability scenarios, the single most important reason an unnecessary UPS really cheeses people off is that a year or two from now, it will start beeping. An UPS needs regular battery ...
Bass's user avatar
  • 601
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
  • 5,391
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
24 votes
Accepted

How to configure UPS to restart servers in the right sequence?

The standard answer for this is "not at all". Fix the software to handle restarts in random order. If you really need SOME servers to start first (example: Active Directory) put them on USV's that are ...
TomTom's user avatar
  • 51.9k
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
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
  • 2,320
17 votes

What are the pros and cons of having your own UPS attached to your own server hosted in a data center?

You may need to run your own UPS when your datacenter doesn't quite deserve the name and it does not provide centralised UPS for you and other customers. On the other hand, if that is the case there ...
HBruijn's user avatar
  • 80.3k
14 votes

How to configure UPS to restart servers in the right sequence?

Managed Power Distributions Units (rather than the UPS) often do support customised delays in enabling individual outlets after power is resumed. Typically that is to prevent circuit breakers from ...
HBruijn's user avatar
  • 80.3k
10 votes

What are the pros and cons of having your own UPS attached to your own server hosted in a data center?

Don't forget the Electrical Code. Most have something like NEC 110.3b, "equipment must be used according to its labeling and instructions".* That gives the instructions the same force of law as the ...
Harper - Reinstate Monica's user avatar
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

How do I pick a UPS for a graphics rendering machine?

You pick a UPS the same way you always pick a UPS: You measure the power consumption of the server under typical load (for you that will be when actually rendering) You figure out the runtime you ...
Mark Henderson's user avatar
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

ZFS - enable or disable disk cache?

You should definitely enable the disk cache. The rationale is that ZFS assumes enabled disk cache and so flushes any critical writes (ie: sync write and uberblock rewrite) via appropriate and ...
shodanshok's user avatar
  • 50.7k
6 votes

How to configure UPS to restart servers in the right sequence?

I had this exact issue. The only difference being we invested in sturdy rack mounted APC power units (for example APC SmartUPS 3000 ). With the APC PowerChute network shutdown software (PowerChute ...
Winski Tech's user avatar
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
  • 7,034
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
Accepted

Can I power 2x6 socket surge protected PDUs from a surge protected UPS?

No, you shouldn't use surge protected PDUs. Instead, use a plain, quality PDU without surge protection. This is recommended by APC. Also, read this for some nice background explanation.
Sven's user avatar
  • 99.6k
5 votes

APC UPS replace battery illuminates

A battery can hold between 1 and 10 years. This depends on many factors like: battery lot, storage conditions, usage conditions. If the capacity suddenly dropped to a very low value, it means the ...
Overmind's user avatar
  • 3,141
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

Change the UPS battery while it's powered on?

I "Hot Swapped" 3 APC Smart UPS 1500 batteries at three different power plants here in southern California. These UPS systems are used to power the CAISO RIG (California Independent System Operator ...
Tony Medina'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

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

Can't get upsmon service started to monitor (and respond to) remote UPS

You need to edit /etc/nut/upsd.users (on buffalo.local in your case) and define a upsmon user, like so: [yourupsmonuser] password = somerandompassword upsmon master Then in /etc/nut/upsmon.conf (on ...
Ola Tuvesson's user avatar
4 votes
Accepted

How can I fix my UPS repeatedly disconnecting and reconnecting?

Inspired by this post, the solution for me so far has been to create a new udev rule: # /etc/udev/rules.d/62-nut-usbups.rules SUBSYSTEM!="usb", GOTO="nut-usbups_rules_end" # TrippLite # e.g. ...
Layne's user avatar
  • 101
3 votes
Accepted

What is the difference between the "Write" and "Write+" modes on an APC SNMP card?

A user with write+ access can issue SNMP writes when another user is logged into the web interface, a user with write cannot. SNMP reads are unaffected.
bodgit's user avatar
  • 4,771
3 votes
Accepted

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

My initial and immediate thoughts are along the lines of what you're contemplating. If these blips are occurring independent of any self-test schedules you have set up on the UPS (if the blips happen ...
vigilem's user avatar
  • 589
3 votes

UPS inside server room?

No risk, but make sure the A/C got enought BTU for your servers, as such big UPS produce heat too. I did a comparaison on a normal UPS, SmartAPC 1500 vs an Eaton 40kva, and both product follow the ...
yagmoth555's user avatar
  • 17.1k

Only top scored, non community-wiki answers of a minimum length are eligible