Backing Up Linux

Linux is easier to just do things on than most operating systems. It especially shines, however, when it comes to shell scripting. With bash and a text editor, there’s not much you can’t automate. Today I wrote a shell script to back up my documents (which can be found in /home/yourname on just about any Linux system) to a USB flash drive mounted as disk The script, incidentally, is three lines long.

1. #!/bin/bash
2. cd /home
3. tar czvf "/media/disk-1/backup/backup-`date +%s`.tar.gz" /home/ian

That’s it. This backs up /home/ian with tar to a compressed file with the name equal to “backup-” + the number of seconds since midnight on January 1, 1970 + “.tar.gz”.

If you want to exclude files or folders from the backup, just add “–exclude=filename” to line 3.

How large is a CD?

The real answer is 120 millimeters in diameter, large enough to hold 80 minutes of audio. The fun answer, the answer you really want to know can be found on Wikipedia.

The partners aimed at a playing time of 60 minutes with a disc diameter of 100 mm (Sony) or 115 mm (Philips). Sony vice-president Norio Ohga suggested extending the capacity to 74 minutes to accommodate Wilhelm Furtwängler’s 1951 performance of Beethoven’s 9th Symphony.

The extra 14 minute playing time subsequently required changing to a 120 mm disc. Kees Immink, Philips’ chief engineer, however, denies this. According to a Sunday Tribune interview, the story is slightly more involved. At that time (1979) Philips owned Polygram, one of the world’s largest distributors of music. Polygram had set up a large experimental CD plant in Hanover, Germany, which could produce huge amounts of CDs having, of course, a diameter of 115 mm. Sony did not yet have such a facility. If Sony had agreed on the 115 mm disc, Philips would have had a significant competitive edge in the market. Sony decided that something had to be done. The long playing time of Beethoven’s Ninth imposed by Ohga was used to push Philips to accept 120 mm, so that Philips’ Polygram lost its edge on disc fabrication.

Another Record by Apple

Every Tuesday so far this year, Apple has released a product. Some Tuesdays, more than one. There’s been the new Mac Pros, the MacBook Air, Time Machine, iTunes Movie Rentals, the new Apple TV software, new iPod Touch and new iPhones, and now Aperture 2.

This is a record on the part of Apple; 8 new products in only 7 Tuesdays. If they keep this up, they’ll have introduced more than 60 new products by the end of the year. How long do you think they’ll be able to hold out?

Recommended Listening #1

This week’s music:

Movement 3 (O Waly, Waly)

from Suite for Strings, by John Rutter.