Features (). HAMMER file system provides configurable fine-grained and coarse-grained filesystem histories with online snapshots availability. Up to 65536 master (read-write) and slave (read-only) pseudo file systems (PFSs), with independent individual retention parameters and inode numbering, may be created for each file system; PFS may be mirrored to multiple slaves both locally or over.
In some ways, you can't compare them: XFS is a filesystem; ZFS is a filesystem and so much more: it replaces the filesystem, the volume manager (like LVM), and RAID besides. However, JFS is no longer maintained if memory serves: however, XFS is active and maintained and robust. Either way - ZFS or XFS - you can't go wrong in my opinion.
There are no wine or linux emulation layer in OpenBSD. Here is a small list of most well known games that run on OpenBSD: 'dig' a little deeper. I knew the existence of the dig command but didn't exactly know when and how to use it. Then, just recently I encountered an issue that allowed me to learn and make use of it. HAMMER2 and periodic snapshots. The first version of HAMMER took automatic.
FreeBSD ZFS vs. TrueOS ZoF vs. DragonFlyBSD HAMMER2 vs. ZFS On Linux Benchmarks Phoronix With TrueOS offering daily snapshots built agai.
DragonFly BSD 5.6. DragonFly version 5.6 brings an improved virtual memory system, updates to radeon and ttm, and performance improvements for HAMMER2. 5.6.1 fixes a misconfiguration in sshd and a lockup in ttm. 5.6.2 fixes a number of bugs, and includes a disruptive change to TCP timeouts. What is DragonFly BSD?
The big news with DFBSD5 is that the Hammer2 filesystem has finally released with it. Hammer has long been one of the more advanced filesystems on the market and Hammer2 is a major update to it. Hammer2 currently supports live dedupe, compression, fast recovery and snapshots. Multi-volume and clustering are not yet available, but are coming.
FreeBSD 9 will parallel Linux in terms of scalability: NUMA, multi-core granularity, advanced scheduling. Meanwhile, FreeBSD also has stable and current ZFS support. HAMMER seemed interesting in theory but grandiose for such a small developer community and userbase. Now Dillon admits that the design was flawed and proposes and even more.
The HAMMER filesystem is also intended to serve as a basis for the clustering and other work that makes up the second phase of the project. Note that in the most recent release of the operating system (release 5.0), HAMMER2 does not support clustering. Also read this (somewhat old) InformIT article: DragonFly BSD: UNIX for Clusters.