NetBSD-Users archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: ZFS
On Thu, 3 Mar 2016, coypu%SDF.ORG@localhost wrote:
Someone on IRC implied that he is using ZFS. Still struggling to
believe, so I gotta ask - is there anyone out there using it?
I'm not. I never knew it got past the idea stage for NetBSD. It's listed
on the projects page here:
https://wiki.netbsd.org/projects/project/zfs/
Did it ever get to the point where it was usable? The last note on the
project page says "It is not finished. Ask on tech-kern for more
information about the current state." but it's dated 2014.
Like you, I wonder about ZFS in general. Didn't the NetBSD project pay
someone to complete it or am I wrong and it was a purely volunteer effort?
Was it part of a Google SoC project? Can it ever be pulled into the
mainline code (ie.. isn't the CDDL incompatible with the BSD license?) ?
ZFS has some great features. I've used it quite a bit under Solaris and
FreeBSD. However, it's also proven to be a source of a lot of crashes I've
seen under both (but especially FreeBSD).
I'm guessing it'd be a really big challenge to re-implement things like
deduplication or other key ZFS features, but then again I look at HAMMER
and wonder... Since HAMMER is BSD-focused (and BSD licensed) maybe that's
a better choice to want to throw in with ? Then again, I don't know the
politics of that, either.
A few tidbits about ZFS:
* Solaris never has had LVM. Sun had a history of making spectacularly
bad choices before ZFS came along. Those of you who have tried to
recover a mis-matched SDS/SVM rig know what I mean. They had a chance to
get VxVM on the cheap in the 90's and pooched it (while HP-UX, Tru64,
and UnixWare snatched it up). So, NetBSD has RAIDframe which works
nicely, and now a very sweet LVM. The urgency to have something like ZFS
in NetBSD shouldn't be quite as acute as it was in Slowlaris.
* I don't consider having block storage commands separated from file
system commands a weakness. Ie.. LVM + FS == ZFS && ! ZFS > everything.
I think that puts me on the outs with the cool kids.
* If you put all the storage features in NetBSD up against ZFS, the main
things you come up missing on are:
- Huge sizes on all the upper limits. The "zettabyte" part is real.
- Deduplication
- online fsck (scrub)
- An unprecedented level of paranoia about data integrity
However, of those only deduplication is all that exciting. Other ZFS-like
features we have (if you consider the full NetBSD toolset):
- Block device encryption
- Ability to grow a file system (don't think UFS in NetBSD can shrink)
- Block device abstraction, aggregation / RAID (LVM / RAIDframe)
- File system snapshots
- Root disk mirroring
Other stuff I'm not sure about:
- Can NetBSD do RAID6 / RAID-DP in software ?
- What about the ZIL and L2ARC, are there already NetBSD equals?
- Does NetBSD's LVM support multiple copies of an LV on physical PVs
ala ZFS ditto blocks ?
- Does anyone care that ZFS is now closed source and the CDDL forks are
now going to drift significantly from the parent core ? I don't
really, but I'm just wondering if that's a concern.
- Do we have anything against HAMMER ? I personally think it's cool.
It's an interesting topic to me.
-Swift
Home |
Main Index |
Thread Index |
Old Index