zfs discuss - May 2008 - Why root zone can''t be on ZFS for upgrade ?

This is an old discussion but maybe someone could help me clarify a couple of
things.

Having not known taht zone root file systems can''t be ZFS, we built
several of these zones in our production environment. We are running Solaris 10
8/07. We now see that Zone roots are not supported on ZFS file systems.

I would like to get the following answered, if possible.

1. What file systems can be used for the Zone root file system?
2. Will the supported file system not have the same problems as ZFS in the
future?
3. If we continue using ZFS as the root file system, and we run into upgrade
problems in the future, would be be able to do a dump of the zone root from  ZFS
to the correct file system that is supported by zones?

Thanks in advance,
Luke
 
 
This message posted from opensolaris.org

On Wed, May 7, 2008 at 9:59 AM, Luke Schwab <lukeschwab at yahoo.com>
wrote:
> This is an old discussion but maybe someone could help me clarify a couple
of things.
>
>  Having not known taht zone root file systems can''t be ZFS, we
built several of
> these zones in our production environment. We are running Solaris 10 8/07.
We
> now see that Zone roots are not supported on ZFS file systems.
>
>  I would like to get the following answered, if possible.
>
>  1. What file systems can be used for the Zone root file system?
Currently, UFS.
>  2. Will the supported file system not have the same problems as ZFS in the
future?
Not likely, see below.
>  3. If we continue using ZFS as the root file system, and we run into
upgrade
> problems in the future, would be be able to do a dump of the zone root from
> ZFS to the correct file system that is supported by zones?
I don''t see any reason that would not work.

        Digging in a little bit deeper, the reason that Zone Root FS
is not supported on ZFS is the problem of OS upgrades. When you do an
OS upgrade you are booting off of install media and running off of a
Mini-Root that is loaded in RAM. Currently the Mini-Root does not
include ZFS (or MPxIO, so SAN devices with multiple paths are out as
well). But, if you do a Live Upgrade instead of a regular offline
upgrade, you should be OK.

        NOTE: I have not tried this yet (but it is an my agenda as we
want to put *all* of a zone on ZFS), but is based on my understanding
of how OS installs and upgrades, and ZFS work as well as conversations
with technical people at Sun. The unofficial recommendation I got was
that as long as you understand the limitations, go right ahead and use
ZFS for all of the Zone''s FSes. Once I complete lab testing here, I
plan on posting results back here and to the zone-discuss lists.

-- 
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Paul Kraus
-> Facilities Coordinator, Albacon 2008