Linked by Thom Holwerda on Sun 14th Oct 2007 14:52 UTC, submitted by Oliver
Matthew Dillon writes: "I am going to start committing bits and pieces of the HAMMER filesystem over the next two months. Note that the filesystem will not be operational until we get closer to the 2.0 release in December so these bits and pieces will not be tied into buildworld/buildkernel until then." Features: maximum size of half an exabyte, infinite snapshots, limited only by retention policy, streaming backups, asynchronous transactional support (no long fscks to check disk state). Dillon also explains why he chose not to use Sun's ZFS.
Thread beginning with comment 278332
To view parent comment, click here.
To read all comments associated with this story, please click here.
To view parent comment, click here.
To read all comments associated with this story, please click here.
Member since:
2005-07-06
I'm not an expert on the subject, but I'd say that ZFS consists of two parts, the FS and the "IO stack". The FS is the actual filesystem (on disk data layout etc.) while the IO stack is the rest that makes ZFS special.
HAMMER is very similar in that it will also have two parts, the FS and the rest. The actual FS does not have to take particularly long to develop if you are familiar with FSes (like Matt) and do not try to make something truly revolutionary. The rest is probably the harder part, but the idea of a clustered file system is not new and Matt has been working a few years towards this goal and I would guess that a lot off the grunt work is already done.
As an example, the (FS independent) journaling was implemented as far back as 2005, and it is my understanding that it will play an important role when replicating across machines. Also, in February Matt posted an initial outline of HAMMER, so for those who claim that it will be done in record time: I'm not so sure, this is something he has been working on for quite some time now.