Can DragonFlyBSD's HAMMER Compete With Btrfs, ZFS? Written by Michael Larabel in Software on 7 January 2011 at 01:00 AM EST. Page 1 of 3. 29 Comments. The most common Linux file-systems we talk about at Phoronix are of course Btrfs and EXT4 while the ZFS file-system, which is available on Linux as a FUSE (user-space) module or via a recent kernel module port, gets mentioned a fair amount too. When