DragonFlyBSD 5.0 is the first release with preliminary boot support for HAMMER2, the project’s new filesystem.
Preliminary HAMMER2 support has been released into the wild as-of the 5.0 release. This support is considered EXPERIMENTAL and should generally not yet be used for production machines and important data. The boot loader will support both UFS and HAMMER2 /boot. The installer will still use a UFS /boot even for a HAMMER2 installation because the /boot partition is typically very small and HAMMER2, like HAMMER1, does not instantly free space when files are deleted or replaced.
Awesome to see HAMMER2 support for booting! HAMMER2 is one of the coolest parts of Dragonfly, and this new version (with improved portability) is really exciting to see hitting real systems.
in a few bullet points, what’s so good about HAMMER?
(i did try to google it .. )
Go here:
https://www.dragonflybsd.org/hammer/
HAMMER2 looks like it is an interesting alternative for ZFS / btrfs. Compression, deduplication, low memory footprint, even possible to use it in a cluster.
https://gitweb.dragonflybsd.org/dragonfly.git/blob_plain/HEAD:/sys/v…
Music. Can you touch this ?
There is this comparison (from 2015) between ZFS and HAMMER: https://forums.freebsd.org/threads/49789/
Note that the version of HAMMER referred to there is HAMMER1. HAMMER2 has most of the missing features, including self-healing capabilities and compression, as well as an attempt at improved portability.
As an avid user of his DICE C compiler on the Amiga back in the old days, and a fan of DragonFlyBSD (with its own filesystem and the slab allocator) I think it’s safe to say that Matthew Dillon is a genius.
Edited 2017-10-18 03:09 UTC
Don’t forget Blink, that linker saved me a lot of space on my Amiga disks.
Of course he is.
He was by far ahead of the time when implementing multicore support for FreeBSD, he implemented lightweight threads, usermode kernel on DragonFly, HAMMER and a lot of very technical stuff.
He does not get all the glory that deserves.