Friday was kind of interesting. The talks were little weaker, but there were some interesting ones. For example, Matt Mackall’s Towards a Better SCM: Revlog and Mercurial talk was a nice way to learn how Mercurial stores the history. I got tired so I went back to the hotel, and fell asleep for few hours. I woke up just in time to head over to the conference center for the 20:00 Stackable file systems BOF. That was interesting. A lot of useful people showed up, including Christoph Hellwig, Ted Tso, Val Henson, Steve French (Samba/CIFS guy), Jan Blunck,Eric Van Hensbergen (plan9 fs implementation in Linux) and many more. Topics included limited stackspace (4K on i386), cache consistency, locking, and nameidata structure brain damage.
As we planed before, after the BOF we invited everyone over to the hotel for some snacks and drinks. That’s where things got really interesting. I spent a lot of time with Jan Blunck and Eric Van Hensbergen talking about the proper way to do unions. Three people, three different ways to union files :)
After that we had some fun with the stack space issue and Reiserfs (and Hans’s approach to open source).
- stack space
- There should be a competition "who can create the largest storage stack without overflowing the stack." For example, unionfs on top of gzipfs on top of versionfs on top of device mapper on top of md on top of scsi over ethernet on top of ppp tunneled thought ssh …. you get the idea
- Apparently, Christoph once fixed something trivial in reiserfs code, he sent the patch to Hans, and in return he got a gigantic legal document (I know exactly what he is talking about as I have submitted a patch once as well). Well, he didn’t like it, so he gave Hans a bunch of options one of which included certain sum of money for copyright to the code. Interestingly enough, Hans accepted. Too bad I didn’t know about this story before, I might have made some money of off my one line fix to the reiserfs section in the Kconfig file. :)
I have to say, I really want to look at how plan9 works thanks to the conversation I had with Eric Van Hensbergen. It seems to have a lot of really good ideas. Hrm, now that I think about it, I might install it one of my old boxes. Yeah, I know I am odd.