DragonFlyBSD's HAMMER2 File-System Being Ported To NetBSD

[phoronix]

Phoronix: DragonFlyBSD's HAMMER2 File-System Being Ported To NetBSD

NetBSD continues using the FFS file-system by default while it's offered ZFS support that has been slowly improving -- in NetBSD-CURRENT is the ability to use ZFS as the root file-system if first booting to FFS, for example. There may be another modern file-system option soon with an effort underway to port DragonFlyBSD's HAMMER2 over to NetBSD...

https://www.phoronix.com/news/NetBSD-HAMMER2-Port

[Steffo]

who had also worked on porting HAMMER2 to FreeBSD as another exercise

LOL, didn't Mat Dillon explained, that this is technical not possible, because of missing features in FreeBSD?

[ehansin]

Stop, it's HAMMER time!

https://www.youtube.com/watch?v=T_wS0Kw6k9c

[uid313]

How good is HAMMER2 compared to other file systems such as ext4, ZFS, Btrfs, and Apple File System (APFS)?

Are they similar in design or does HAMMER2 provide any advantages?

Has there been any interest to port HAMMER2 to Linux? I think it would be difficult because Linux and DragonFly BSD differ in the VFS.

[evert_mouw]

How good is HAMMER2 compared to other file systems such as ext4, ZFS, Btrfs, and Apple File System (APFS)?

Are they similar in design or does HAMMER2 provide any advantages?

Has there been any interest to port HAMMER2 to Linux? I think it would be difficult because Linux and DragonFly BSD differ in the VFS.

Seems difficult:

https://news.ycombinator.com/item?id=15068802

ZFS and HAMMER2 both have native encryption support. Btrfs has something planned in the future, but given its track record, many people will not have much confidence in it. HAMMER2 has a more permissive license. The best hope for native ZFS-like fs kernel support is maybe Bcachefs. APFS lives in an altogether different ecosystem.

I'm not sure if HAMMER2 will get clustering support (it is in the design doc) but that would be interesting. Recently, remote block-level mounts over the network were made possible.

[archkde]

LOL, didn't Mat Dillon explained, that this is technical not possible, because of missing features in FreeBSD?

I suppose porting to FreeBSD involves adding the missing features.

[danboid]

"in NetBSD-CURRENT is the ability to use ZFS as the root file-system if first booting to FFS" sounds like a contradiction to me. I think it means to say its not currently possible to boot directly from ZFS root in netbsd ie you need a FFS boot partition?

[Michael]

"in NetBSD-CURRENT is the ability to use ZFS as the root file-system if first booting to FFS" sounds like a contradiction to me. I think it means to say its not currently possible to boot directly from ZFS root in netbsd ie you need a FFS boot partition?

https://wiki.netbsd.org/wiki/RootOnZFS/

[kpedersen]

I suppose porting to FreeBSD involves adding the missing features.

Indeed. Same with ZFS. Infact, FreeBSD has a solaris.ko (kernel module) just for these additions.

I am glad to hear hammer is getting ported. Mainly because if you port it once, it helps you clean up some of the encapsulation and API making it easier to port to further operating systems.

[dreich]

I suppose porting to FreeBSD involves adding the missing features.

As it the case with most things getting ported from foreign systems. On Linux this used to be achieved thanks to the Solaris Porting Layer (SPL) which resided on a its own repository and has been merged into ZFS.