
The sixth major
DragonFly BSD release, version 1.10, was
announced today by project creator Matthew Dillon. Billed as "more stable than the 1.8 release", it includes improved virtual kernel support, a new disk management infrastructure, improvements to wireless networking, and support for the new syslink protocol. As to what all that means, KernelTrap has just posted an
interview with Dillon. Going beyond today's 1.10 release, the interview explores DragonFly's new clustering high-availability filesystem which sounds superior to ZFS, the project's goals for the 2.0 release expected in six months, and a comparison of the BSD license versus the GPL.
Member since:
2005-07-08
There are two main differences between DF's clustering filesystem and ZFS. First, it's intended to (eventually) manage storage devices that are distributed amongst several cluster nodes. Also, it uses live snapshots for redundancy as well as for backup, eliminating the need for an integrated storage layer.
I was surprised to learn that the Matt is developing the clustering filesystem via the userspace VFS API instead of putting it in the kernel. Perhaps there are plans to port it to the kernel once the userspace implementation reaches a certain milestone.
My theory on filesystem design calls for a heap-like storage layer that provides a logical extent abstraction to client filesystems. Filesystem consistency can be guaranteed with proper design, while physical storage is subject to unavoidable corruption and failure. So it makes more sense (to me) to implement redundancy at the storage level rather than at the filesystem level.
But Matt hails from the world of commercial database development, so he has a good handle on these sorts of things.
Edited 2007-08-07 16:14