Groundhog day: Debugging BrandZ linux, repeatability
By bnitz on Feb 03, 2006
I know that the groundhog's official winter forcasting day was yesterday, but I was just thinking about the movie, Groundhog Day, where Bill Murray plays a weatherman who must relive the same day over and over again until he gets it right. The reason I was thinking about this is that I was debugging some problems while trying to get Postgres and a Kylix based application to behave together within a BrandZ zone. Other than a few weird things about the way kylix creates ELF binaries, most of my problems have been configuration and RPM version issues. One cool thing about BrandZ is that it allowed me to tar up my working linux environment, send it off to a BrandZ expert who could recreate my problem, create a patch and send the patch back to me. Another cool thing is that if I somehow manage to misconfigure my linux environment or an install overwrites something, I can go back to the tarball and have the linux environment from yesterday (Groundhog day) up and running in just a few minutes.
What I haven't done, but should be possible, is use ZFS's filesystem snapshot and rollback feature to more efficiently capture snapshots of my work-in-progress so that I can always go back an hour or two to the latest working environment. BrandZ isn't yet complete, but is anyone else using it for debugging linux applications?