port HAMMER FS? (and bounty)

["Jeremy C. Reed" <reed%reedmedia.net@localhost>]

Anyone interested in porting HAMMER file system from DragonFly to NetBSD?

I attended the HAMMER presentation this last weekend at NYCBSDCon and 
listened to other discussions. To summarize:

- address up to 1-Exabyte

- 50GB is the suggested minimum

- inode numbers never reused 

- doesn't reference by blocks, so doesn't have to deal with device 
  knowledge

- doesn't overwrite metadata

- records everything you have ever done on file system

- define when to do snapshots

- reblocking and pruning to free information / recover space / delete file 
  system history via cron jobs

- mirroring

- pseudo file systems

- snapshots accessed via special symlinks

- will support multi-master mirroring

- currently slave pseudo file system is read-only

- later plan: share duplicated data (use same physical block)

- later plan: add file system validation

- later plan: network accessible

Details at http://www.dragonflybsd.org/hammer/index.shtml follow links to 
manual pages and PDF which has a beginning of "Porting" instructions.

Also a hammer mailing list is setup for "Porting" plans.

By the way, see
http://searchenterpriselinux.techtarget.com/news/article/0,289142,sid39_gci1334319,00.html
 
which says about GPL'd file system development: "The cost of the 
undertaking, which is too expensive for any single company to underwrite, 
will be shared among a number of corporate backers, each of which will 
contribute to the task in various ways and in accordance with their 
abilities and fiscal constraints, he said."

If you don't know there is a bounties webpage at 
http://wiki.netbsd.se/Bounties