Its time to break out the calculators and do some math. There are two main factors at work here, UPS load capacity and battery run time. I run a series of research clusters at a university, so only the core systems (landing pads, schedulers, auth, disk arrays) are on UPS and all the compute nodes just die at a power hit.

Retrofitting a datacenter for whole center UPS is a very daunting and expensive task, so odds are good you'll be replacing the current rack mounts with beefier units, either pedestal sized units next to their racks or rack mounted units.

When buying UPS gear for work, I aim to hit either 67% capacity with the planned load, or the smallest VA rating that takes 208V single phase, as long as its at least 1/3 under utilized for future expansion. That covers the VA rating. As for battery run time, most of the larger units accept external battery packs to increase the run time. I've never used them, since a 5KVA unit with my load gives me 20 minutes of run time, and if the power isn't back on by then, odds are good its not coming back any time soon.

Another option for extending UPS run time is to prioritize services/VMs. With the appropriate monitoring software on each host, you can configure each host to shutdown when the UPS estimates X minutes of battery time remaining or there have been Y minutes on battery, or both. Less load, more run time for the really important stuff. Almost every UPS I've used (APC, Tripp-lite, Powerware) comes with off the shelf software or there are opensource solutions (apcupsd, nut) for monitoring the UPS over serial, USB, or SNMP (Options vary with mfg and model). My shutdown schedule is: after 5 minutes on battery, power down the compute cluster landing pads. With 10 minutes remaining, power down the file servers with the archival data on them. With 6 minutes remaining, power down the primary file servers. With 2 minutes remaining, power down the auth box/network monitor/iLom control host (This is the only one that can't get powered on/monitored remotely).

Does your university have a backup solution you can make use of? The one I work at lets researchers onto their Tivoli system for the cost of the tapes. I think I've got somewhere in the neighborhood of 100TB on the system and ended up being the driving force behind a migration from LTO-2 to LTO-4 this summer. If you are going to go and role your own and use disks, I'd recommend something with ZFS - you can make a snapshot after every backup so you can do point in time restores.

Also, I'd recommend more capacity on backup than you have now to allow versioning. I was the admin for a university film production recently (currently off at I believe Technicolor being put to IMAX) and I've lost track of the number of times I had to dig yesterday's or last week's version off of tape because someone made a mistake that was uncorrectable.

As of Friday, your only options for ZFS support will be (Open) Solaris and FreeBSD. Apple decided ZFS wasn't compatible/ready/something and removed it.

I have data sets spanning multiple terabytes. One recent PhD graduate in the lab I support accumulated 20 TB of results during his time here. Even if I had highly reliable SSDs that never failed, I'd still toss the SSDs together in a zpool to get the capacities I need to accommodate a single data set. RAID is not just about redundancy. With SSDs, I'd probably use RAID5 instead of RAID6 just in case I had a freak bad drive, but RAID in some form is here to stay.

Which story? Quake, Doom, or Half-life (not iD, but originally an iD engine)

I belive Unix was first developed on a PDP-7 as PDP-11s did not yet exist in 1969.

See also Open Firmware on Power/PPC and I believe the firmware interpreter on SGI MIPS systems was also Forth based.

It got MIPS too. At least in the high end server/workstation market. Though I don't miss IRIX.

Last time I looked at LED stagelights about a year ago, the LED PAR64 can seemed to be a drop in replacement for 300W PAR56 lamps. Unfortunately, until intensity catches up to their higher wattage cousins, most of the stages I've worked on are going to keep dropping in 750W HPL, 1KW BVT, and 1K PAR64 lamps. The biggest advantage is its easier to get a blue of out an LED than a halogen, for obvious reasons, but losing the light among the other fixtures isn't really desired all the time.