RAID - Redundant Arrays of Inexpensive Disks

I was talking with my brother Andy this morning about the wisdom of buying aBlue-Ray player, which sent my mind off on a tangent about how fast you could stream data from a hard disk drive. Hard drives can read and write data pretty quickly once the data has been located on the disk. However, locating the track where the data is stored can be a very slow process, relatively speaking. I just looked up a Western Digital disk that has a average seek time of 7 milliseconds, which is an eternity in a computer. However, track-to-track seek time is only 0.7 milliseconds. Still slow, but considerably faster. However, if you had a bunch of disks all lined up and you could switch between them, you could read (or write) from them successively. While you are reading a track from one, which should only take 10 microseconds for a 10,000 RPM disk, all the rest of the disks would be in the process of moving their read/write heads to the next track (seeking). Dividing the 0.7 millisecond seek time by 10 microseconds gives you 70, which means you would need 70 disks to be able to maintain the maximum data transfer rate for this particular model of disk. 70 disks times 500 gigabytes is 35 terabytes. Given the posted data transfer rate of 3 GB/second, it would take 12,000 seconds, or 200 minutes, or 3.3 hours to transfer all of the data that these disks could hold. That's ten terabytes per hour.

What you would do with all that data is another issue.

Blogger Posting

I just discovered that the number of posts per page was still set to 105. I set it to 105 to facilitate creating a backup copy of my blog before I left. I THOUGHT I had reset it to seven, but either I failed, or Google failed to record it. Anyway, it should be set to seven now so it should not take forever and a day to load.

Midwest Tour

I have had several surprising experiences lately and I have not figured out how to write about them without offending someone.

Right now I am hanging out in Fort Madison and reading "The Confusion" by Neal Stephenson, a really excellent book. I am enjoying it immensely.

I am using Andy's laptop to write this and it is sitting flat on a table which makes it difficult for me to type, so this is the end of this post.

Octopus

OCTOPUS I 126.20m (414') I Lurssen I Luxury motor yacht for charter
Camper & Nicholsons
Ross sent me a link to a slide show of Paul Allen's yacht "Octopus". The first slide is kind of garbled, but the rest are good. Paul Allen is (was?) one of Bill Gates' sidekicks at Microsoft and owner of the Trailblazers, the Portland NBA team.

I imagine that the only way to top this would be to get it featured in a James Bond movie.

Update August 2025 replaced dead link with video.

ftp - File Transfer Protocol

A few weeks ago I ran into a situation where I needed to use ftp to upload a file to the internet. Poking around I came across one site that sounded promising but turned out to be worse than useless. I was going to tell them what I thought, but you have to sign up. Yeah, that's just what I want a membership with a really stupid web site. Dummkopfs.

Their suggestions only work on sites that have implemented the necessary features, which means almost none. For any normal site you will need an ftp client program.

A little more searching turned up gftp & filezilla, both ftp client programs for Linux.

gftp installed, but would not run. That was all the effort it got from me. If it doesn't work the first time, I'm not going to spend any time on it.

Used filezilla instead. It installed and ran fine. They have versions for Windows, Linux & Mac.

"Witch Hunt" by Ian Rankin

"Witch Hunt" by Ian Rankin. I think I probably picked this up in a bargain bin somewhere, sometime, I don't remember exactly.

A better than average thriller. There were a few things that bothered me, but they did not crop up often enough to make me quit reading. One was the neurotic, petty complaints people had about their co-workers. They may be a fact of life, but I am not interested. I have plenty of my own to deal with.

Another is when the head of the department flys to Germany to rein in an over zealous agent. I don't think it would have happened that way. The agent would no doubt be called on the carpet on his return, but I don't think the boss would have made a public show of it. Better to keep things like that in the family, so to speak. Going to pick up the wayward soul would only serve to advertise the loss of control. Better to pretend it was all part of the plan in the first place. This section might have made a good dramatic section in a movie version, and maybe that was what the writer was angling for. On the other hand, it did not ring true, and I doubt it would ring true in the movie. But hey, it's a thriller, not an intellectual exercise, so what can you expect?

There was another incident that struck me as false, but I cannot remember it right off. Of course, the whole thing was based on a wacko premise to begin with, but it made a good story.

Wood Cutting

Jack, John & I went shooting out in the woods yesterday afternoon. After blasting away at some close range tin cans, we took aim at a slightly more distant target: an empty quart can about 100 to 150 feet away. John impaled it on a branch so it wouldn't move, even when hit. We had been shooting at it for a while when we noticed that the log the can was attached to had broken. We went to investigate this miraculous happening and found several perforations in the log along with one bullet that hadn't quite made it all the way through. You can see the little circle of metal poking through the wood in the middle right of the last picture.