Why Are You NOT Using FreeBSD ?

[David Magda]

On Jun 1, 2012, at 21:03, Chris Nehren wrote:

> You say your'e using ZVOLs but then recommend gluster for large
> filesystems. I would like to take a moment to point out that one of the
> design goals of ZFS was to scale beyond the capabilities of current
> hardware. 
> 
> What does gluster do that ZFS does not? I'm not trying to troll here,
> but am genuinely curious about ZFS's shortfalls in one of the problem
> domains it seeks to address.

ZFS is for storing file systems on locally connected block devices. Gluster is a network file system where data can be distributed over many nodes.

So ZFS can ensure that bits-on-disk stay safe through checksums and mirroring / RAIDZ, while Gluster allows entire file servers to go offline and the files are still accessible because you have a kind of network-level RAID going on. This also helps in performance since instead of clients pounding on one file server (as usually happens with NFS), every write is sent to many data nodes so you're striping across many network elements. Think of it as NFS on steroids.

A competitive open source equivalent would be Lustre, while Isilon and Panasas would probably be commercial alternatives (though they do NFS / CIFS on the 'front-end' and the distributed "magic" occurs on a 'back-end' network between the appliances).

http://en.wikipedia.org/wiki/GlusterFS
http://en.wikipedia.org/wiki/Lustre_(file_system)