GFS2 and OCFS2 are 2 cluster filesystems in linux kernel. We also support GFS2, though most of our customers use OCFS2 as we recommend. Last hackweek, from a user perspective, I learned about the difference of usage, features and performance between them. This time, I'd like to look into the design of GFS2 from a developer side.

Goals I want to achieve:
1. Look back a bit history of ocfs2 and gfs2 when they were merged into kernel;
2. Learn about the disk layout of gfs2;
3. Get the idea of how gfs2 manages its meta-data and data;
4. To known the way how gfs2 employs DLM;
5. Get the current status of gfs2 relative packages on SUSE.