zfs discuss - Jan 2011 - OS restore to first hard disk on ZFS while booted from second had disk

Hi,

I have a Solaris 10 x86 server with 2 hard disks running on mirrored UFS
configuration.

Currently we are trying to implement a OS backup solution using Networker 7.6. I
can successfully backup the OS to a remote Networker server.

But now the trouble is if I need to perform a full Solaris OS restore, I need to
perform an installation of the Solaris 10 base OS and install Networker 7.6
client to call back the data from that Networker server.

However I do not like the idea of restoring the Solaris OS by overwriting an
existing installation.

Hence, I thought of a way by performing an initial installation of the Solaris
10 base OS and Networker on the second disk. Then partition and newfs the first
disk and then restore the OS from the Networker server to that first disk. The
server is able to function correctly upon reboot. Subsequently the second disk
is mirrored to the first disk.

The above solution works perfectly but now with things on ZFS, it becomes more
complex.

Does anyone know if I can perform the above with ZFS filesystem (excluding the
Networker setup)?

I just need to know the following:

1) create a ZFS filesystem on the first disk (with similar ZFS configuration
before the server failed)
2) install the bootblk on that first disk
3) Upon reboot, mirror the first disk to the second using zfs

If the above 2 can be done then performing the OS restore to that disk (assuming
that the base OS and Networker client was installed on the second disk) should
not be an issue.

regards,
LD
-- 
This message posted from opensolaris.org

On 01/24/11 09:13 PM, Ddl wrote:
> Hi,
>
> I have a Solaris 10 x86 server with 2 hard disks running on mirrored UFS
configuration.
>
> Currently we are trying to implement a OS backup solution using Networker
7.6. I can successfully backup the OS to a remote Networker server.
>
> But now the trouble is if I need to perform a full Solaris OS restore, I
need to perform an installation of the Solaris 10 base OS and install Networker
7.6 client to call back the data from that Networker server.
>
> However I do not like the idea of restoring the Solaris OS by overwriting
an existing installation.
>
> Hence, I thought of a way by performing an initial installation of the
Solaris 10 base OS and Networker on the second disk. Then partition and newfs
the first disk and then restore the OS from the Networker server to that first
disk. The server is able to function correctly upon reboot. Subsequently the
second disk is mirrored to the first disk.
>
> The above solution works perfectly but now with things on ZFS, it becomes
more complex.
>
> Does anyone know if I can perform the above with ZFS filesystem (excluding
the Networker setup)?
>
> I just need to know the following:
>
> 1) create a ZFS filesystem on the first disk (with similar ZFS
configuration before the server failed)
> 2) install the bootblk on that first disk
> 3) Upon reboot, mirror the first disk to the second using zfs
>
> If the above 2 can be done then performing the OS restore to that disk
(assuming that the base OS and Networker client was installed on the second
disk) should not be an issue.
>
See the root pool recovery process in the ZFS admin guide, now at

http://download.oracle.com/docs/cd/E19963-01/821-1448/gavwg/index.html

-- 
Ian.

> From: zfs-discuss-bounces at opensolaris.org [mailto:zfs-discuss-
> bounces at opensolaris.org] On Behalf Of Ddl
> 
> But now the trouble is if I need to perform a full Solaris OS restore, I
need to
> perform an installation of the Solaris 10 base OS and install Networker
7.6
> client to call back the data from that Networker server.
For a bare metal restore, your strategy revolves entirely around what type
of boot media you have.  If your backup tool doesn''t include bare metal
boot
media for your OS, you could install a temporary "throw away" OS onto
something like a removable disk in order to use Networker to restore, blah
blah blah.  

Personally, I think if your backup tool doesn''t support bare metal
restore,
including boot media for your OS, it''s time to reconsider your backup
strategy.  Sure, use Networker for your primary data, but keep that on a
pool separate from rpool.

Chicken and egg.  "I need Networker to restore the OS I need in order to
use
Networker."  Also ... I trust native filesystem tools more than 3rd party
tools for complete backup of the filesystem.  That is, for the OS, I trust
"zfs send" more than any 3rd party backup tool.

If you "zfs send" the rpool somewhere, where it can easily be fetched
and
piped into a "zfs receive" without using Networker or any other 3rd
party
backup software...  Then you can boot into command prompt on the Solaris
installation DVD, and use zfs receive to restore your OS.  This is the
strategy that I use, and I''ve restored successfully this way several
times.
Be aware, that ssh is not one of the available tools in the solaris boot
DVD.  The easiest thing is probably NFS.

> Hence, I thought of a way by performing an initial installation of the
Solaris 10
> base OS and Networker on the second disk. Then partition and newfs the
> first disk and then restore the OS from the Networker server to that first
> disk. The server is able to function correctly upon reboot. Subsequently
the
> second disk is mirrored to the first disk.
> 
> The above solution works perfectly but now with things on ZFS, it becomes
> more complex.
Why is it more complex in ZFS?  I don''t see any obstacle for you to do
the
above, using a ZFS rpool instead of UFS.

> I just need to know the following:
> 
> 1) create a ZFS filesystem on the first disk (with similar ZFS
configuration
> before the server failed)
> 2) install the bootblk on that first disk
> 3) Upon reboot, mirror the first disk to the second using zfs
All of this is described in the ZFS Troubleshooting Guide.  At least ...
enough clues are there for you to figure it all out.  

Unfortunately, the guide seems to be down right now.  So I can''t tell
you
which part specifically to read.  But all the important nuggets are there...
How to NFS mount a remote system using the boot CD ... installgrub ... how
to slice the OS disk properly...