Discussion:
SVM > ZFS
(too old to reply)
Morris Hooten
2013-02-26 20:30:30 UTC
Permalink
Besides copying data from /dev/md/dsk/x volume manager filesystems to new
zfs filesystems
does anyone know of any zfs conversion tools to make the
conversion/migration from svm to zfs
easier?

Thanks


Morris Hooten
Unix SME
Integrated Technology Delivery
***@us.ibm.com
Office: 720-342-5614
Jim Klimov
2013-02-26 23:05:31 UTC
Permalink
Post by Morris Hooten
Besides copying data from /dev/md/dsk/x volume manager filesystems to
new zfs filesystems
does anyone know of any zfs conversion tools to make the
conversion/migration from svm to zfs
easier?
Do you mean something like a tool that would change metadata around
your userdata in-place and turn an SVM volume into a ZFS pool, like
Windows' built-in FAT -> NTFS conversion? No, there's nothing like it.

However, depending on your old system's configuration, you might have
to be careful about choice of "copy" programs. Namely, if your setup
used some ACLs (beyond standard POSIX access bits), then you'd need
ACL-aware copying tools. Sun tar and cpio are some (see manpages about
usage examples), rsync 3.0.10 was recently reported to support Solaris
ACLs as well, but I didn't test that myself. GNU tar and cpio are known
to do a poor job with intimate Solaris features, though they might be
superior for some other tasks. Basic (Sun, not GNU) cp and mv should
work correctly too.

I most often use "rsync -avPHK /src/ /dst/", especially if there are
no ACLs to think about, or the target's inheritable ACLs are acceptable
(and overriding them with original's access rights might even be wrong).

Also, before you do the migration, think ahead of the storage and IO
requirements for the datasets. For example, log files are often huge,
compress into orders of magnitude less, and the IOPS loss might be
negligible (or even boost, due to smaller hardware IOs and less seeks).
Randomly accessed (written) data might not like heavier compressions.
Databases or VM images might benefit from smaller maximum block sizes,
although often these are not made 1:1 with DB block size, but rather
balance about 4 DB entries in an FS block of 32Kb or 64Kb (from what
I saw suggested on the list).

Singly-written data, like OS images, might benefit from compression as
well. If you have local zones, you might benefit from carrying over
(or installing from scratch) one as a typical example "DUMMY" into a
dedicated dataset, then cloning it into many actual zone roots as you'd
need, and "rsync -cavPHK --delete-after" from originals into this
dataset - this way only differing files (or parts thereof) would be
transferred, giving you the benefits of cloning (space saving) without
the downsides of deduplication.

Also, for data in the zones (such as database files, tomcat/glassfish
application server roots, etc.) you might like to use separate dataset
hierarchies mounted via delegation of a "root" ZFS dataset into zones.
This way your zoneroots would live a separate life from application
data and non-packaged applications, which might simplify backups, etc.
and you might be able to store these pieces in different pools (i.e.
SSDs for some data and HDDs for other - though most list members would
rightfully argue in favor of L2ARC on the SSDs).

HTH,
//Jim Klimov
Paul Kraus
2013-02-26 23:10:22 UTC
Permalink
Post by Jim Klimov
Post by Morris Hooten
Besides copying data from /dev/md/dsk/x volume manager filesystems to
new zfs filesystems
does anyone know of any zfs conversion tools to make the
conversion/migration from svm to zfs
easier?
However, depending on your old system's configuration, you might have
to be careful about choice of "copy" programs. Namely, if your setup
used some ACLs (beyond standard POSIX access bits), then you'd need
ACL-aware copying tools. Sun tar and cpio are some (see manpages about
usage examples), rsync 3.0.10 was recently reported to support Solaris
ACLs as well, but I didn't test that myself. GNU tar and cpio are known
to do a poor job with intimate Solaris features, though they might be
superior for some other tasks. Basic (Sun, not GNU) cp and mv should
work correctly too.
Under Solaris 10 I found 'cp -pr' to be the both most reliable and fastest way to move data into, out of, and between ZFS datasets.

--
Paul Kraus
Deputy Technical Director, LoneStarCon 3
Sound Coordinator, Schenectady Light Opera Company
Jim Klimov
2013-02-26 23:19:07 UTC
Permalink
Ah, I forgot to mention - ufsdump|ufsrestore was at some time also
a recommended way of such transition ;)

I think it should be aware of all intimacies of the FS, including
sparse files which reportedly may puzzle some other archivers.
Although with any sort of ZFS compression (including lightweight
zle) zero-filled blocks should translate into zero IOs. (Maybe
some metadata would appear, to address the "holes", however).
With proper handling of sparse files you don't write any of that
voidness into the FS and you don't process anything on reads.

Have fun,
//Jim
Paul Kraus
2013-02-26 23:36:55 UTC
Permalink
Post by Jim Klimov
Ah, I forgot to mention - ufsdump|ufsrestore was at some time also
a recommended way of such transition ;)
The last time I looked at using ufsdump/ufsrestore for this ufsrestore was NOT aware of ZFS ACL semantics. That was under Solaris 10, but I would be surprised if the ufsrestore code has changed since then.

--
Paul Kraus
Deputy Technical Director, LoneStarCon 3
Sound Coordinator, Schenectady Light Opera Company
Alfredo De Luca
2013-02-27 03:15:32 UTC
Permalink
what about Solaris live upgrade?
Post by Paul Kraus
Post by Jim Klimov
Ah, I forgot to mention - ufsdump|ufsrestore was at some time also
a recommended way of such transition ;)
The last time I looked at using ufsdump/ufsrestore for this
ufsrestore was NOT aware of ZFS ACL semantics. That was under Solaris 10,
but I would be surprised if the ufsrestore code has changed since then.
--
Paul Kraus
Deputy Technical Director, LoneStarCon 3
Sound Coordinator, Schenectady Light Opera Company
_______________________________________________
zfs-discuss mailing list
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
--
*Alfredo*
Ian Collins
2013-02-27 03:30:25 UTC
Permalink
Post by Paul Kraus
Post by Jim Klimov
Ah, I forgot to mention - ufsdump|ufsrestore was at some time also
a recommended way of such transition ;)
The last time I looked at using ufsdump/ufsrestore for
this ufsrestore was NOT aware of ZFS ACL semantics. That was under
Solaris 10, but I would be surprised if the ufsrestore code has
changed since then.
what about Solaris live upgrade?
It's been a long time, but I'm sure LU only supports UFS->ZFS for the
root pool.
--
Ian.
Alfredo De Luca
2013-02-27 03:48:35 UTC
Permalink
Not sure


http://docs.oracle.com/cd/E19253-01/821-0438/ggzdo/index.html
Post by Alfredo De Luca
Post by Paul Kraus
Post by Jim Klimov
Ah, I forgot to mention - ufsdump|ufsrestore was at some time also
a recommended way of such transition ;)
The last time I looked at using ufsdump/ufsrestore for
this ufsrestore was NOT aware of ZFS ACL semantics. That was under
Solaris 10, but I would be surprised if the ufsrestore code has
changed since then.
what about Solaris live upgrade?
It's been a long time, but I'm sure LU only supports UFS->ZFS for the root
pool.
--
Ian.
______________________________**_________________
zfs-discuss mailing list
http://mail.opensolaris.org/**mailman/listinfo/zfs-discuss<http://mail.opensolaris.org/mailman/listinfo/zfs-discuss>
--
*Alfredo*
Darren J Moffat
2013-02-27 11:22:16 UTC
Permalink
Post by Morris Hooten
Besides copying data from /dev/md/dsk/x volume manager filesystems to
new zfs filesystems
does anyone know of any zfs conversion tools to make the
conversion/migration from svm to zfs
easier?
With Solaris 11 you can use shadow migration, it is really a VFS layer
feature but it is integrated into the ZFS CLI tools for easy of use

# zfs create -o shadow=file:///path/to/old mypool/new

The new filesystem will appear to instantly have all the data, and it
will be copied over as it is access as well as shadowd pulling it over
in advance.

You can use shadowstat(1M) to show progress.
--
Darren J Moffat
Alfredo De Luca
2013-02-27 22:35:09 UTC
Permalink
Hi Darren. you're right! With solaris 11 and shadow migration feature it's
fantastic.

Not sure which Solaria vers we are talking about here.

Alfredo



On Wed, Feb 27, 2013 at 10:22 PM, Darren J Moffat
Post by Darren J Moffat
Post by Morris Hooten
Besides copying data from /dev/md/dsk/x volume manager filesystems to
new zfs filesystems
does anyone know of any zfs conversion tools to make the
conversion/migration from svm to zfs
easier?
With Solaris 11 you can use shadow migration, it is really a VFS layer
feature but it is integrated into the ZFS CLI tools for easy of use
# zfs create -o shadow=file:///path/to/old mypool/new
The new filesystem will appear to instantly have all the data, and it will
be copied over as it is access as well as shadowd pulling it over in
advance.
You can use shadowstat(1M) to show progress.
--
Darren J Moffat
______________________________**_________________
zfs-discuss mailing list
http://mail.opensolaris.org/**mailman/listinfo/zfs-discuss<http://mail.opensolaris.org/mailman/listinfo/zfs-discuss>
--
*Alfredo*
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