Building a new server rack (help with power)

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jediatzinger

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  • #1
    I have 5 servers that run our small business. We're going to be moving and I'm going to be setting up a new rack space. I'd like to get these on battery power for backup (short-term backup to handle light power outages, etc). I know the uptime isn't going to be long, but if the power "blinks" I don't want my servers turning off/restarting.

    Server diagram

    2 of the servers aren't listed as they're VM. 3 physical, 2 virtual. The space under the "tower" server is a shelf... couldn't find a good Visio stensil for it.

    How would you best setup this rack and servers power wise? Would you get a dedicated battery backup for each of the physical hosts? I have redundant PS so I could connect PS1 to the second battery so they're split across two so there isn't a single point of failure.

    I was thinking 1:1. One PDC for each server then one battery. The PDC is nice because it displays the power requirement. I don't know a lot about PDCs so if there is a better option I'd love to hear about it. I was planning on using CyberPower PDU15M2F8R and PR1500RT2UC for battery backups.

    How would you design the power setup?
     
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    SandyTech

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  • #2
    First question I'd ask is what kind of budget you're working with, as that influences recommendations quite a bit. Brand wise? Eaton or Vertiv all the way.

    We use single Eaton 9PXs series UPSes, plus the service/ATS transformer and additional battery modules to make up extra runtime where needed for a lot of customers. Most cases we will also feed an Eaton monitored/switched 0U PDU, though some customers we will just use an unmetered PDU. In the event the UPS completely fails we can (and have) walked customers through shunting the bypass across to get them up temporarily rather than buy a second power head.
     
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    DrWebster

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    If you have redundant PSUs in your equipment and the budget for it, a pair of rackmount UPS units would be best. One UPS for all servers' PSU side 1, the other for PSU side 2. That way you'll survive an individual PSU failure, individual UPS failure, or utility outage including some combinations of those two (as unlikely as that may be). You may or may not need a PDU depending on how many sockets on are the UPS units you choose, but you should be sizing the UPS based on the maximuim practical load the servers will draw anyway. Better rackmount UPS units have network connectivity for monitoring and clean shutdown of servers if the battery is running out.
     
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    jediatzinger

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  • #4
    DrWebster said:
    If you have redundant PSUs in your equipment and the budget for it, a pair of rackmount UPS units would be best. One UPS for all servers' PSU side 1, the other for PSU side 2. That way you'll survive an individual PSU failure, individual UPS failure, or utility outage including some combinations of those two (as unlikely as that may be). You may or may not need a PDU depending on how many sockets on are the UPS units you choose, but you should be sizing the UPS based on the maximuim practical load the servers will draw anyway. Better rackmount UPS units have network connectivity for monitoring and clean shutdown of servers if the battery is running out.
    Click to expand...
    I'd like to be able to view the power consumption (the front of the PDU listed displays the amps). It's not a requirement, but if I'm building what I want I'd like to be able to know the power draw. Is this something I could see from the battery? The battery should cover what I'd need from a outlet count.
     
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    sryan2k1

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  • #5
    DrWebster said:
    If you have redundant PSUs in your equipment and the budget for it, a pair of rackmount UPS units would be best. One UPS for all servers' PSU side 1, the other for PSU side 2. That way you'll survive an individual PSU failure, individual UPS failure, or utility outage including some combinations of those two (as unlikely as that may be). You may or may not need a PDU depending on how many sockets on are the UPS units you choose, but you should be sizing the UPS based on the maximuim practical load the servers will draw anyway. Better rackmount UPS units have network connectivity for monitoring and clean shutdown of servers if the battery is running out.
    Click to expand...
    Budget unlimited sure but we just plug the 2nd PSU of everything into utility power to avoid a SPOF
     
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    oikjn

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  • #6
    sryan2k1 said:
    Budget unlimited sure but we just plug the 2nd PSU of everything into utility power to avoid a SPOF
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    Thats pretty budget indeed. How about at least a surge suppressor on that utility power.

    Personally, unless you are really proactive about testing and battery replacement, I'd push for 2x UPS just because they do have a tendency of not delivering what you expect when you don't keep the batteries up to date.
     
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    sryan2k1

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  • #7
    oikjn said:
    Personally, unless you are really proactive about testing and battery replacement, I'd push for 2x UPS just because they do have a tendency of not delivering what you expect when you don't keep the batteries up to date.
    Click to expand...
    We replace the batteries when our Eaton's tell us to do so, never had an issue so far (although we know that isn't impossible)
     
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    DrWebster

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  • #8
    jediatzinger said:
    I'd like to be able to view the power consumption (the front of the PDU listed displays the amps). It's not a requirement, but if I'm building what I want I'd like to be able to know the power draw. Is this something I could see from the battery? The battery should cover what I'd need from a outlet count.
    Click to expand...
    A few options here. A lot of rackmount UPS units have a front panel LCD to show status, including current draw. If you plug your servers directly into the UPS, then it'll show the aggregated consumption. If you want per-server stats, then you'd need to look into networked PDUs, which can give you the draw on each socket (and optionally allow you to toggle power to each socket). If you're only concerned about the draw from the servers and not any other equipment in the rack (switches, etc) then the easiest way is probably to just get lights-out management on the servers (iDRAC, iLO, etc), which usually includes power supply statistics.
     
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    sryan2k1

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  • #12
    CPX said:
    Speaking on this one, say you were given a few UPS with NICs but no idea what the IP address is and your system runs on vSphere and puppet...what is the best approach to monitoring? Still a Windows VM/workstation?
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    Reset the NIC and monitor it with what you use to monitor everything else, observium in our case.
     
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    Kyuu

    Kyuu

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  • #13
    Depending on your budget and requirements, you may want to look into using UPSes with lithium-iron batteries rather than traditional lead-acid. The up-front cost is higher, of course, but the battery will last the lifetime of the unit so battery swaps are a thing of the past (barring any manufacturing defects of course), and the TCO over its lifetime will roughly balance out. You don't have to worry about battery degradation resulting in unexpectedly low run times. It also makes moving around and installing the units much less back-breaking.

    I've begun migrating my organization over to Vertiv Liebert PSI5 Lithium-Ion UPS models, been going great. The only downside I've found so far beyond the up-front cost is that all UPS manufacturers seem to have decided that the line-interactive lithium-ion UPS lines don't get to have battery expansion options, even though their equivalent lead-acid lines often did. You have to move up to the pricier (though not that much pricier with Vertiv at least) online double-conversion models.
     
    Kyuu

    Kyuu

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  • #17
    I've yet to encounter any equipment that is sensitive enough where line-interactive UPSes aren't a quick enough response to a power event. But if you want double-conversion, the Vertiv Liebert GTX5 Lithium-Ion models are great too. We have one going where we wanted an external battery cabinet for more run-time. (I swear I don't work for Vertiv.)
     
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    oikjn

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  • #19
    Kyuu said:
    I've yet to encounter any equipment that is sensitive enough where line-interactive UPSes aren't a quick enough response to a power event. But if you want double-conversion, the Vertiv Liebert GTX5 Lithium-Ion models are great too. We have one going where we wanted an external battery cabinet for more run-time. (I swear I don't work for Vertiv.)
    Click to expand...
    Depends on how dirty your power is and what you want to protect against. In our case, we are an industrial manufacturer and when the big equipment runs, it can distort the power... not enough to trigger any UPSes and not enough to immediately cause failures, but enough to shorten device lifespans and cause random crap to occur. In those cases, the extra cost for the equipment and the extra % in utility consumption more than makes up for its ability to generate a power line that is 100% isolated from the harmonics that can sneak through a line-interactive unit when every PSU these days is filled with Capacitors that really don't appreciate much THD%
     
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