DragonFly BSD


DragonFly BSD 4.8

DragonFly version 4.8 brings EFI boot support in the installer, further speed improvements in the kernel, a new NVMe driver, a new eMMC driver, and Intel video driver updates.

The details of all commits between the 4.6 and 4.8 branches are available in the associated commit messages for 4.8RC, 4.8.0, and 4.8.1.

Big-ticket items

Improved kernel performance

This release further localizes cache lines and reduces/removes cache ping-ponging on globals. For bulk builds on many-cores or multi-socket systems, we have around a 5% improvement, and certain subsystems such as namecache lookups and exec()s see massive focused improvements. See the corresponding mailing list post with details.

Support for eMMC booting, and mobile and high-performance PCIe SSDs

This kernel release includes support for eMMC storage as the boot device. We also sport a brand new SMP-friendly, high-performance NVMe SSD driver (PCIe SSD storage). Initial device test results are available.

EFI support

The installer can now create an EFI or legacy installation. Numerous adjustments have been made to userland utilities and the kernel to support EFI as a mainstream boot environment. The /boot filesystem may now be placed either in its own GPT slice, or in a DragonFly disklabel inside a GPT slice.

DragonFly, by default, creates a GPT slice for all of DragonFly and places a DragonFly disklabel inside it with all the standard DFly partitions, such that the disk names are roughly the same as they would be in a legacy system.

Improved graphics support

The i915 driver has been updated to match the version found with the Linux 4.6 kernel. (Linux 4.7 in the DragonFly 4.8.1 release.) Broadwell and Skylake processor users will see improvements.

Other user-affecting changes



MD5 (dfly-x86_64-4.8.0_REL.img) = 7936811dc0113bb5a5c607d3bfd71917
MD5 (dfly-x86_64-4.8.0_REL.iso) = e6811893c02e99ca7dd8f3c1d6e92ae3
MD5 (dfly-x86_64-4.8.0_REL.img.bz2) = 0e0a426ea581b9057ef1277b2ba7167d
MD5 (dfly-x86_64-4.8.0_REL.iso.bz2) = 54bd900737a32fab9939ec5fd1fd0d6d


If you have an existing 4.6.x system and are running a generic kernel, the normal upgrade process, described below, will work.

Note that DSA OpenSSH keys are now deprecated. It's possible to change your configuration to allow DSA keys again, but we recommend moving to a new key when possible. If you only have DSA keys, change to another type before upgrading or you may lock yourself out. You may be able to use -oHostKeyAlgorithms=+ssh-dss to get in anyway, but we recommend changing to RSA keys ASAP.

Note that OpenSSH HPN support has been removed. You will need to remove it from your sshd config. This only affects you if you specifically enabled it in your configuration.

Change your local /usr/src to 4.8:

cd /usr/src
git fetch origin
git branch DragonFly_RELEASE_4_8 origin/DragonFly_RELEASE_4_8
git checkout DragonFly_RELEASE_4_8
git pull

And then rebuild: (in /usr/src )

make buildworld
make buildkernel
make installkernel
make installworld
make upgrade

Don't forget to upgrade your existing packages. 4.8 packages have already been built and are immediately available.

pkg upgrade

All changes since DragonFly 4.6




Other drivers


Various tools have been upgraded in the base system:

Hammer Status

Miscellaneous improvements. One thing that didn't make it into the release was a version bump to use a faster CRC algorithm with a different polynomial. This work will be MFC'd to -release once testing is complete. However, users should not worry about it too much because the most serious performance fix IS in the release (a fix to the cluster_write() code for filesystem writes).

Hammer2 Status

Development continues but no word yet on a first release.

Clang status

A starting framework has been added for using clang as the alternate base compiler in DragonFly, to replace gcc 4.7. It's not yet complete. Clang can of course be added as a package.

64-bit status