On 2012-08-09 11:35, Jim Klimov wrote:
2012-08-09 13:57, Karl Wagner wrote:
Hi everyone,

I have a couple of questions regarding FreeBSD's ZFS support.

Firstly, I believe it currently stands at zpool v28. Is this correct?
Will this be updated any time soon?

Also, looking at the Wikipedia page, the updates beyond this are:
29     Solaris Nevada b148     RAID-Z/mirror hybrid allocator.
30     Solaris Nevada b149     ZFS encryption.
31     Solaris Nevada b150     improved 'zfs list' performance.
32     Solaris Nevada b151     One MB block support
33     Solaris Nevada b163     Improved share support

I am not currently interested in encryption, but what are the advantages of the other improvements? If I were to use Solaris 11 11/11 on a small file server (running 16GB RAM and 3TB storage in 2 mirrored pairs) would
I see any improvement in upgrading from v28 created under FreeBSD 9?

From what I gather, ZFS features v29 and beyond are proprietary
to Oracle, so unless their licensing changes and/or the code is
officially legally published as grabbable open-source, it is not
likely that these features will ever appear in non-Oracle ZFS

There is even some FUD regarding the use of same zpool version
numbers for open-sourced reimplementations of identical features
(so open and proprietary zpools are compatible), and whether that
won't be sued.

In the end, the open-sourced ZFS community got no public replies
from Oracle regarding collaboration or lack thereof, and decided
to part ways and implement things independently from Oracle.
AFAIK main ZFS development converges in illumos-gate, contributed
to by some OpenSolaris-derived distros and being the upstream for
Thank you for the info.

Looking at your responses, I believe I may gain some advantage from an upgrade to v28, particularly from the hybrid alloc and 1MB blocks. However, I don't think it is likely to be worth sacrificing compatibility with other solutions.

Regarding licensing, I am not 100% certain of this. I, personally, count my entire home network as a dev platform (much to the dismay of my other half), and use it to learn stuff for work and/or personal projects. I doubt, however, that this fits Oracle's definition of development. This is another good reason for me to maintain "backwards" compatibility, so even if I decide to try out Sol11 I doubt I will be upgrading the pool.


FreeBSD port of ZFS (probably others too).

Lacking an authority to assign zpool version numbers to particular
features, they instead went for enumeratable feature flags which
report whether a particular zfs/zpool format feature is in use
on the pool and supported by the software trying to import it.
New features in the works include modernized compression and
checksum algorithms, among others. Nominal zpool version is 5000
for pools which enabled feature flags, and that is currently
supported by oi_151a5 prebuilt distro (I don't know of other
builds with that - feature integrated into code this summer).

Regarding your other question, what the v29+ features provide,
here's my understanding:
29     Solaris Nevada b148     RAID-Z/mirror hybrid allocator.
The miniature metadata blocks are allocated by mirroring
sectors instead of raidz-encumbering them, which makes
tasks with metadata faster and probably reduces associated
storage and processing overheads.

30     Solaris Nevada b149     ZFS encryption.
Encryption of datasets, pools and/or objects?

31     Solaris Nevada b150     improved 'zfs list' performance.
Probably a performance bump

32     Solaris Nevada b151     One MB block support
Should improve efficiency of large file storage, especially
on modern 4Kb sectored disks, by reducing the needed portion
of metadata overhead and fragmentation (more data is written
sequentially, low-level prefetches win more). Writes on *very
full* pools might suffer, because it is less likely to quickly
find an available block big enough.

33     Solaris Nevada b163     Improved share support
Probably a performance and/or interoperability bump

//Jim Klimov

BTW, are you sure your intended use of Solaris 11 fits into the
free usage license restrictions (dev/POC for Solaris, basically)?
This is not a rhethorical question, because I know some home-users
who were uncertain if they can use Sol11 as their home-NAS OS or
a home desktop or their small office server, and just to be surely
on the safe side, switched to some of the other distros. I would
welcome enlightened comments to this part ;)

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