The Network under the Bright-Bright Sky

If the harddrive growing speed is strictly sticking with the Moore’s Law (so far that’s pretty much the case), and that my data is growing slower than what’s Moore’s Law has predicted, then my server could still hold my data at anytime in the future.

A big assumption: I have to keep forking out money in purchasing new harddrive.

In the Q1 of 2007, I spent a whole lot in buying a 500GB, and it was full for quite some time. I have to stop my data from growing for a while also. While the 1TB harddrive price dropped to HKD $1300 from HKD $3000 when it was released, it’s still pretty expensive. Besides, it looks like my data doesn’t grow as fast (because I watched less Anime recently? who knows-), so I bought a new one the day before and settled with a 640GB.

The old 500GB is then transferred to the backup server. The backup server now have 2*250GB+1*500GB=1TB space available. Comparing with my 100MB  installed in a 386 desktop 19 years ago, it is 10000 times bigger. (That’s about doubling for every 17.1 months, that’s not apple to apple comparison, but anyway). The 320GB from the backup is also offlined so I colud use it to backup my desktop now.

It took 1 day to re-sync the existing 4xxGB through the 100Mbps ethernet. Looks like I must upgrade it to GE next time.

…it’s just a matter of time when you will be punished.

It’s probably because I didn’t have a gratitude, or that I didn’t offer sacrifices to the god of computer on full-moon and new-moon, and I got punished today as a warning.

I was upgrading the Wordpress to 2.6, primarily for testing the compatibility of xLanguage. Of course, the first step is to dump the existing data to the testbed platform. It’s was a very long time when I was doing this last time, but luckily I have left the migration script somewhere. Bang! It’s still working, great!

Then I “diff”ed the part that I customized, and overwrote the existing binaries with 2.6’s as instructed, then patched the “diff”, all green.

I was going back to the Admin panel, was trying to see if the patch still works on 2.6. Before I could get to there, I found that some entries are gone! Now when I was checking the migration script…

“Darn…” I felt an icy wind was breezing over my cold sweating face…Looks like I have managed to reversed the migration direction, I had the production blog database overwritten with an very old testbed data.

I still recalled my Daily backup server was down for a while, original plan is to leave it there until I went back home. And just now, I was pinging it while hoping miracle to happen. No it didn’t happen, the computer returned “ssh: connect to host backup port 22: Connection refused.”

Let’s take a look at the MySQL’s log folder, looks like the God of Computer didn’t abandon me yet.  The Binlog that I turned on earlier is still functioning; I can still dump every SQL statements ever executed on the server.

It took me some time to locate the last blog migration from the binlog, then replaying all the MySQL statements in between. Well, it actually took much longer than I expected to replay 2 month worth of statements, even though I had filtered out the WassUp unless transaction, it was still taking it more than 1 hour to replay the remaining statements.

Take home message: it’s important to have backup, and probably multiple backup. According to a non-scientific survey, almost 90% of data disaster was introduced by Human. Thank god for guiding me over the process, and I should fix my backup server ASAP.

改編《自義勇軍進行曲》
Original - March of the Volunteer

Liberate the ID! Liberate the data!
(more…)

Okay, publishing the work is always the hardest, especially for the first time for a particular project. Now I have Trac and Subversion setup (and BTW, I upgraded Wordpress to 2.5), publishing UsbAvrUsb, hColorLED and UsbHid.

With these software, with a Atmel USB AVR series controller (like AT90USB162) prototype board and some LEDs, you can then control these LEDs to be at any color on the computer, through the shinny USB interface.

Recently I have been involved in some LED side-project, and the whole story by itself should also be blogged…may be in another day.

http://www.amazon.com/Mommy-Why-There-Server-House/dp/160530641X