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Showing posts from October, 2009

No, we are not running out of bandwidth.

The sky is falling! the sky is falling!

Actually, we’re running out of bandwidth (PDF) (again).

Supposedly all the workers who stay home during the pandemic will use up all the bandwidth in the neighborhood. Let me guess, instead of surfing p0rn and hanging out on Reddit all day at work, they’ll be surfing p0rn and hanging out on Reddit all day from home.

The meat of the study:
“Specifically, at the 40 percent absenteeism level, the study predicted that most users within residential neighborhoods would likely experience congestion when attempting to use the Internet” So what’s the problem?
“..under a cable architecture, 200 to 500 individual cable modems may be connected to a provider’s CMTS, depending on average usage in an area. Although each of these individual modems may be capable of receiving up to 7 or 8 megabits per second (Mbps) of incoming information, the CMTS can transmit a  maximum of only about 38 Mbps.” Ooops – someone is oversubscribed just a tad. At least now we know…

Maintenance, Downtime and Outages

Via Data Center Knowledge - Maintenance, Downtime and Outages a quote from Ken Brill of The Uptime Institute:"The No. 1 reason for catastrophic facility failure is lack of electrical maintenance,” Brill writes. “Electrical connections need to be checked annually for hot spots and then physically tightened at least every three years. Many sites cannot do this because IT’s need for uptime and the facility department’s need for maintenance downtime are incompatible. Often IT wins, at least in the short term. In the long term, the underlying science of materials always wins.”Of course the obvious solution is to have redundant power in the data center & perform the power maintenance on one leg of the power at a time. One of our leased spaces does that. The other of our leased spaces has cooling and power shutdowns often enough that we have a very well rehearsed shutdown & startup plan. The point is well taken though. If you don’t do routine maintenance, you can complain about …

Data Loss, Speculation & Rumors

My head wants to explode. Not because of Microsoft's catastrophic data loss. That's a major failure that should precipitate a significant numbers of RGE's at Microsoft.My head wants to explode because of the speculation, rumors and mis-information surrounding the failure. An example: rumors reported by Daniel Eran Dilger in Microsoft’s Sidekick/Pink problems blamed on dogfooding and sabotage that point to intentional data loss or sabotage."Danger's existing system to support Sidekick users was built using an Oracle Real Application Cluster, storing its data in a SAN (storage area network) so that the information would be available to a cluster of high availability servers. This approach is expressly designed to be resilient to hardware failure."and"the fact that no data could be recovered after the problem erupted at the beginning of October suggests that the outage and the inability to recover any backups were the result of intentional sabotage by a dis…