UPS considerations and recommendations

[Umfriend]

Hi all,

I am in the market for a UPS. Obviously I want it to protect the server against power-outs but I also need it to ensure the server is shut down properly in case of such. Aside from capacity and top output, what should I look for? Any recommendations?

Cheers,
Umf

[UtwigMU]

Depends how bad power is there. In Slovenia we have great infrastructure in Ljubljana and power almost never goes out. Maybe once a year if that.

Once I had uptime of 8 months before rebooting. Now my server is up for nearly 3 months - without UPS. I got used APC and I replaced batteries at official service. Less than a year latter server failed because UPS failed. So if you have great electrical network, UPS can be a liability. If I had no UPS, server wouldn't have shutdown, would have rebooted at worst. UPS actually caused downtime.

Where I also work in some village, power is bad and goes out once to few times a month. These are very short outages and I tend to have network equipment, servers on UPS.

I put entire shop with 4 desktop PCs with 19" LCDs, modem, router, NAS and switch on 3000VA UPS and it ran. Before that I ran 2 servers on that. So I'd say for one server 750-1000VA is enough.

Considerations:
- mainly to tide over short outages which would have either caused a reboot
- better is to implement shutdown, this depends on the OS (ESX, Windows...) - make sure it's supported
- make sure batteries are widely available. For example at first I only found batteries for HP UPS somewhere in Holland online. Only then I found out regular cheap motorcycle batteries fit. APC and other popular brands have batteries available but other brands may also use generic batteries
- calculate whether it's worth it to you. For example HP 3000VA batteries cost ~70 EUR and will go bad within 2 years. If you really only loose power once during this time (and windows survives that fine) and you don't need 4 or 5 nines of uptime, it's not worth it. Also you will have to implement shutdown and check batteries. Time is expensive, so consider also this. APC 750 or 1000 (I forgot) batteries cost about ~150 EUR.
- buy used UPS with USB connection (serial is on the way out) and replace batteries, you can get one for a few EUR. It will probably be cheaper than buying a new one unless you have a company and can put it in costs and deduct VAT.
- see also if you need modem cable surge protection (there are UPS that offer this but ADSL speed may drop considerably when run over surge protector, at least this was the case with HP 3000VA.
- batteries at shop which sells car and motorcycle batteries cost much less than in official service center.

If you really have mission critical data, it's better to buy VPS hosting somewhere as it's cheaper than running your own server at home or put your server in a data center. Unless you're a company with multiple physical servers.

[VJ]

I had a MGE Evolution 2200, a quite powerful rackmount UPS.
The proper shutdown is no problem, but I would recommend going to hibernate. Some programs might prevent a shutdown, but not many prevent a hibernate. Also, if your computer was doing something (e.g. computing something or transcoding something), it will continue when it wakes up again. The shutdown/hibernate should be just a windows setting, but the UPS needs to have USB or serial to connect to the server.

One important thing, depending on where you put the UPS: noise! Most UPSes make noise. Some have a cooling fan on all the time, others just have the cooling fan on when they run on battery. But many of them tend to make a high pitched whine which can be quite annoying.

Small suggestion: plug a small led lamp into the UPS, in case there is a power failure, you at least have light there.