zfs discuss - Dec 2009 - Confusion over zpool and zfs versions

I''m running Solaris 10 update 8 (10/09).  I started out using an older
version of Solaris and have upgraded a few times.  I have used "zpool
upgrade" on the pools I have as new versions become available after
kernel updates.

I see now when I run "zfs upgrade" that pools I created long ago are
at version 1 while pools I created more recently have newer versions.
Can anybody clue me into the difference between zpool and zfs
versions?  Are there any compatibility issues with upgrading zfs versions?
Will this affect zfs send/recv to other systems like the zpool version
does?

Thanks for your advice.

I also noticed misleading info in re. the "zfs upgrade -v" message.
It prints a message that says "For more information on a particular
version, including supported releases, see:
http://www.opensolaris.org/os/community/zfs/version/zpl/N"

I know you are supposed to replace the "N" in the web page address
with an integer, but I just copy and pasted it into firefox.  When I
did that, I was redirected to:
http://hub.opensolaris.org/bin/view/Community+Group+zfs/N-1

That page is a list of four links labeled "ZFS File System Version 1"
through "Version 4"  But, following those links brings up the
descriptions of the ZFS Pool versions 1-4, not the ZFS versions.

Thanks again,
Doug
-- 
This message posted from opensolaris.org

Hi Doug,

The pool and file system version upgrades allow you to access new
features that are available for a particular Solaris release. For
example, if you upgrade your system to Solaris 10 10/09, then you
would need to upgrade your pool version to access the pool features
available in the Solaris 10 10/09 release. If you created a new
pool on the same system, then those features would be available
automatically.

Some features are specific to the file system format and some features
are specific to the pool format, hence the different versions.

The compatibility issue for pools is that you will not be able to
import a pool of a later version on a system running an earlier Solaris
version.

Another example is that you can''t send a ZFS send stream with the dedup
flag to a system that doesn''t understand dedup. For some operations,
the
file system can be received, but not mounted on a system at a lower
version.

The pool and fs version is also related, in that if you were running
pool 10 and tried to upgrade to ZFS fs version 4, ZFS would tell you
that you need to upgrade the pool version.

I fixed the problem with the ZFS version pages.

Thanks for reporting it.

Cindy

On 12/17/09 14:12, Doug wrote:
> I''m running Solaris 10 update 8 (10/09).  I started out using an
older
> version of Solaris and have upgraded a few times.  I have used "zpool
> upgrade" on the pools I have as new versions become available after
> kernel updates.
> 
> I see now when I run "zfs upgrade" that pools I created long ago
are
> at version 1 while pools I created more recently have newer versions.
> Can anybody clue me into the difference between zpool and zfs
> versions?  Are there any compatibility issues with upgrading zfs versions?
> Will this affect zfs send/recv to other systems like the zpool version
> does?
> 
> Thanks for your advice.
> 
> I also noticed misleading info in re. the "zfs upgrade -v"
message.
> It prints a message that says "For more information on a particular
> version, including supported releases, see:
> http://www.opensolaris.org/os/community/zfs/version/zpl/N"
> 
> I know you are supposed to replace the "N" in the web page
address
> with an integer, but I just copy and pasted it into firefox.  When I
> did that, I was redirected to:
> http://hub.opensolaris.org/bin/view/Community+Group+zfs/N-1
> 
> That page is a list of four links labeled "ZFS File System Version
1"
> through "Version 4"  But, following those links brings up the
> descriptions of the ZFS Pool versions 1-4, not the ZFS versions.
> 
> Thanks again,
> Doug

Cindy,

Thanks for the info and fixing the web site.

I''m still confused why there are two different things (zpool and zfs)
that need to be upgraded.  For example, is there any reason I would want to
upgrade the zpool and NOT upgrade the zfs?

Thanks,
Doug
-- 
This message posted from opensolaris.org

Hi Doug,

Some features are provided at the pool level and some features are 
provided at the file system level so we have two upgrade paths.

I believe the fs versions were originally created to support ZFS
compatibility with other OSes, but I''m not so clear about this.

I can''t think of any reason why you would not want to upgrade both
versions but maybe someone else can.

Cindy

On 12/18/09 07:37, Doug wrote:
> Cindy,
> 
> Thanks for the info and fixing the web site.
> 
> I''m still confused why there are two different things (zpool and
zfs) that need to be upgraded.  For example, is there any reason I would want to
upgrade the zpool and NOT upgrade the zfs?
> 
> Thanks,
> Doug

>>>>> "d" == Doug  <dy7t at yahoo.com> writes:
     d> is there any reason I would want to upgrade the zpool and NOT
     d> upgrade the zfs?

in theory/hope zfs send streams depend only on the ZFS version being
sent, not on the kernel build or zpool version. In practice I doubt
it''s perfectly true across every single development build ever spun
but it''s the hope, so you might want to keep an old zfs verson so you
could replicate that filesystem into an older zpool.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 304 bytes
Desc: not available
URL:
<http://mail.opensolaris.org/pipermail/zfs-discuss/attachments/20091218/70afeafa/attachment.bin>