ZFS vs. FlexRAID

[dziring]

Can someone help me understand the differences and advantages/disadvantages of ZFS vs. FlexRAID?
They seem to have a number of common goals and features, and I'm curious what makes them different.

 

[jgreco]

ZFS is a filesystem technology developed by Sun Microsystems. Sun had a product called Online: DiskSuite, which handled underlying volume management to create metadevices in a manner similar to FreeBSD's Vinum or CCD, but they had it twenty years ago. They also had products like the PrestoServe (think: ZIL) to help their UFS implementation effectively serve NFS. As one of the major proponents of UNIX servers, one of the major NFS implementations, etc., Sun came to an early and intimate understanding of the ins and outs of UFS. Once it became clear that UFS was showing its age and deficiencies in this new era of cheap storage, Sun needed to have a product that would allow them to be able to credibly store enterprise-level amounts of data, or they would need to cede the storage markets to other players (EMC, IBM, NetApp, etc). So they took their experience and threw it into ZFS, creating a commercial-grade product that they could include on their enterprise-grade servers.

FlexRAID is... I don't even know what it is. Or even if all the things that pop up when you Google it are all talking about the same project. But if it's related to the first link that pops up on Google, that project says it is trying to build FlexRAID on top of ZFS.

http://flexraid.wikkii.com/wiki/Developpement_Status

It looks like some attempt to do some sort of data protection at the file level via a userland system of programs, but that's just my impression from a few minutes of reading and finding no obvious synopsis of what the technology is supposed to be.