Hacker News Reader

Here's a nice explanation of how ZFS does triple parity raid with reed-solomon:

http://people.freebsd.org/~gibbs/zfs_doxygenation/html/da/dc...

http://people.freebsd.org/~gibbs/zfs_doxygenation/html/d1/d7...

Note that the Plank paper claimed to support arbitrary N+M, but was then amended six years later identifying a critical flaw that invalidates its claims. Nevertheless, the technique can be adapted to work for up to triple parity.

So better than most, but still not arbitrary. And the limiting factor seems to be write performance.

Reply on news.ycombinator.com