Working with Ubuntu - Observations

I wrote earlier in the week about installing Ubuntu. Here are more impressions as I work with the distribution, primarily developing with it.

• Building a kernel doesn't work. I pulled kernel 2.6.12.3 from kernel.org and attempted to build it with a config file I had from Fedora Core 4. The config allowed for successful builds and boots on FC4. But when I attempted to do the same here, I got a "Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(3,7)". One other oddball aspect of this failure is the size of the initrd image: it's over 9Mb in size. I've never built one that big before, and it's double the size of the stock 2.6.10 kernel that comes with Ubuntu.
• Running Java works after some tweaking. I have Java installed "on the side" and provide access to it by defining JAVA_HOME and adding $JAVA_HOME/bin to the path. I placed that information in /etc/profile and /etc/bash.bashrc during testing. The problem was that even though I could open a shell and use Java, when I tried to invoke Eclipse 3.1 from a desktop launcher, Eclipse would fail saying it couldn't find Java. I eventually solved the problem by adding a soft link from inside Eclipse to the JRE. In this case, I changed directory to /opt2/eclipse and then types 'ln -s /opt2/java/jre'. This created a soft link to the JRE and Eclipse then started up without a problem.

I don't know what I'll do next. I have several solutions to try before threatening the dreaded wipe-and-reinstall tango. I'm really curious what's so special about building a kernel. I'll start investigating that by building 2.6.12.3 with the Ubuntu configuration. I do like Ubuntu. I'm just perplexed by some the kernel issues I've run into.