Updates and Backups

Evidently the best backup concept is worth jack if you do not implement it. I learned that the hard way yesterday. I “updated” my NSLU2 (“oberon”) from Debian Etch to Lenny which, due to the ARM ABI change required reinstalling.

For backing up my machines I mainly use faubackup wrapped in a script which does things as saving the dpkg package state or dumping my PostgreSQL/OpenLDAP databases. This works and has proven invaluable numerous times.

On the 4th of September 2008 I started tracking my weight loss. I pondered using OpenOffice.org’s Calc, but I deeply dislike spreadsheet programs. So I figured that my NSLU2 is sturdy enough to bear this load, too, and installed PostgreSQL 8.1 (which is in Etch) on it. Since then I quite regularly checked the data in.

Now yesterday I “upgraded” to Lenny. Not without precaution, of course:

• I dd’ed all three USB sticks into a respective image file, even the one containing only a swap partition.
• I specifically ran my faubackup script.
• I deleted unneccesary things from /
• I moved necessary things (/etc, /root, /var) out of the way

The “upgrade” worked fine. Everything was up and running roughly six hours later (bearing in mind, that an NSLU2 has 32 MiB RAM and a 266 Mhz CPU). Everything? No! PostgreSQL wasn’t. Turns out I simply forgot to include my “dump PostgreSQL” stanza to my NSLU2 backup script! And, seeing that the universe hates me, PostgreSQL X.Y database files are not compatible with PostgreSQL X.Z database files. Bummer.

So I had three options to obtain a database dump: Backing up my NSLU2 again and resetting it to its Etch state, relying on emulation or recompiling the Etch PostgreSQL 8.1 packages for Lenny. I decided to go for emulation, just for the fun of it and because everything was working so far. Apart from that recompiling would probably lasted until today and I would not even be sure if the database files could be read correctly (again:  ABI change!).

All in all it took another six hours just to retrieve those data sets. QEmu is dog slow emulating a different CPU architecture (as suspected) and was even slower than my NSLU2. But luckily I found some prepared Etch ARM images. So I only needed to install PostgreSQL 8.1 in them and drop the database files in the right location, and voilà: dumping done, data retrieved, everyone lucky .

MPD

MPD, the Music Player Daemon, is a nice piece of software for playing, you guessed it, music! Now that my main laptop seems to be dying it appears a better alternative than some years ago. Also, due to the ABI change, playing Ogg Vorbis files does not simply kill the machine anymore, but just crackles a little bit. Not a problem, as I cannot access my music collection right now and mostly listen to the liveIreland stream.

Other things of interest

Nothing important to report, really:

• I am feeling a little bit better now than I did the last few days.
• Tomorrow I will try updating my WLAN router to the newest OpenWRT RC.
• I nearly killed my small laptop by spilling water on it (stupid reality).
• I got me some movies from a leftover christmas gift voucher and promptly watched one with Alex today.