Bear Den Designs

Hard drive recovery

My home server’s hard drive and the backup drive failed on the same day, so I’m trying to extract whatever I can from the bad disk. Here are my notes so far:

Boot the dead machine with a Linux live CD; the failed drive won’t mount because the main superblock is one of the sectors that failed.

Make a disk image on a remote machine:

$sudo dd if=/dev/hda bs=512 conv=noerror,sync | ssh user@othermachine:server_hd_backup

conv=noerror tells dd to skip over bad sectors; conv=sync tells it to pad the holes with zeros, so that the resulting disk image will still have everything that it can read in the right place.

Ubuntu gutsy, fglrx and battery life

I have a Thinkpad T60p, which is a nice top-of-the-line laptop with a Core2Duo and an ATI FireGL V5250 video card, but the battery life hasn’t been so good, especially when compared to my older T40, which easily lasted through cross-country flights on those rare occasions when I traveled in that fashion.

I updated to Ubuntu gutsy yesterday, which has Intel’s nifty powertop utility included. That revealed a number of power-hogging things I hadn’t really been thinking about, but my power usage stayed up over 20W and powertop was showing nearly 150 wakeups per second, all the time.

ATI’s proprietary driver has been flagged as a power hog by the people behind powertop, but I didn’t realize just how bad it was until I disabled it and tried powertop again. I’m down to 13.5W and 10-11 wakeups per second at idle; this extends my estimated battery life by over 2 hours!

Other people have noticed that newer versions of the fglrx driver are much improved, but unfortunately the released versions don’t yet support the FireGL cards.

Quickcam STX on Ubuntu

I just bought a Logitech Quickcam Communicate STX for teleconferencing with Skype 2.0 beta on Ubuntu 7.10. Getting it working was …. trivial. True Plug-and-Play; I didn’t even need a driver CD, it just worked as soon as I plugged it in. Hurray!