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Comment: Commercial satellites will not use this (Score 1) 128

by Tolaris (#35237050) Attached to: Sysbrain Lets Satellites Think For Themselves

Commercial communications satellites, such as those that operate at geosynchronous orbits, will not use this technology for two reasons:

1. A satellite which fires a thruster for too long for ANY reason is just gone. Once it's spinning, not where it is expected to be, or otherwise unable to communicate with its control center, it's dead. Dead with $300m down the gravity well.

2. A geosynchronous satellite's lifetime is determined by its thruster fuel. The satellite must make periodic corrections to maintain its "stable" position. Engineers carefully order these thruster adjustments every few weeks or months. If the satellite were free to do it itself, every mistake would reduce lifetime and increase the cost of that satellite's radio capacity (which is what pays back the launch investment).

The question is - do you trust the engineers or the software more? I doubt Intelsat will adopt this until it's been tested by someone whose primary motive is not profit.

Comment: It's called a filter (Score 5, Informative) 109

by Tolaris (#34405114) Attached to: Internet Routing, Looming Disaster?

No, each ISP chooses what routes to accept from what peers. It's called a filter. Smart ISP use routing databases like RIPE to verify what they'll accept and reject automatically. Others do it by hand. Dumb ones accept updates from peers without filtering. It's this last group that needs to update their practices.

Comment: Do the math, and then buy APC (Score 1) 260

by Tolaris (#31129364) Attached to: UPS Setup For a Small/Mid-Size Company?

First, do the math. Calculate the run-time power consumption of your servers. The easiest way is to use real numbers from the existing UPS units, or by using a kill-a-watt.

Second, buy APC UPS units to meet your need. UPSes are rated for the number of actual watt-hours they support. If your servers consume 1500 watts, and you need them to operate for 30 minutes on battery, you'll need at least 750 watt-hours. Considering adding 50% for battery deterioration, and future expansion.

No, I don't work for APC, but they have worked exceedingly well for me and they are supported on practically any operating system you run.

In my network, we have a Linux machine monitor the UPS via USB serial cable using apcupsd, which you can find in your distro's repository. Then all the other machines are linked to that machine also using apcupsd but with an ethernet target instead of USB. When the UPS fails, the others find out within 20 seconds (or whatever your poll time is), and take action. Any data the USB host has, the others have from the network. It is easy to fetch the data via SNMP, graph it in Cacti, etc.

"We are on the verge: Today our program proved Fermat's next-to-last theorem." -- Epigrams in Programming, ACM SIGPLAN Sept. 1982