About :: TODO :: Blog :: RSS :: Old blog :: Projects :: GIT :: Gallery :: Notes

Mon, 26 Feb 2007

Dillon's Infinitely Snapshotable And Segmented Transactional Exabyte Repository. [ND]


Excellent!

That is about upcoming DragonflyBSD filesystem.

After I read its design in details, I can only say that it is not a design, but some very initial draft, so it is early to discuss even ideas.

What rises a question for me is its segmentation.
Storage is divided into segments, each one has some special header to indentify inner blocks, segments can be transformed inot bigger and smaller ones. (one problem I see right now is its indexing, which is 16bits only, while segment size is 4Gb maximum, so we end up with 48-bits addressing mode only).

Interesting ideas, which I plan in my FS too are unlimited snapshotting and absence of log structure to store history of file changes.
I also plan to replicate suberblock (as all fs should do anyway), which was not highlighted in Dillon's paper. I also plan to have plugin layer (which should be able to be turned off to not show a red flag for Linux FS developers) and likely unified cache for directory entries, inodes and pages.

/devel/fs :: Link / Comments ()