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Date: Wed, 5 Nov 2008 13:36:10 -0800
From: Steve Kargl <sgk@troutmask.apl.washington.edu>
To: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>
Message-ID: <20081105213610.GA29688@troutmask.apl.washington.edu>
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	<20081105220050.A20422@wojtek.tensor.gdynia.pl>
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Cc: freebsd-questions@freebsd.org
Subject: Re: Method to mirror a single partition across the net.
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On Wed, Nov 05, 2008 at 10:01:24PM +0100, Wojciech Puchar wrote:
> >following issue.
> >
> >I would like to mirror a single partition on system A to a
> >a partition on system B.  It would appear a combination of
> >gmirror and ggated would work, but I haven't found any
> >example on setting up two systems.
> you are right.
> 
> just create device with ggatec and insert it to the mirror.

Thanks for the reply.  Perhaps, I'm missing an important detail,
but gmirror(8) seems to suggest that it operates on an entire
disk.  Note, in my original email I used the word partition
but showed a disk slice.  I really do mean a partition within
a slice.  Does the following work where I want to mirror only
192.168.0.20:/dev/ad4s1e to 192.168.0.21:/dev/ad4s1e?

On 192.168.0.21:

  # umount /dev/ad4s1e
  # echo "192.168.0.21/24 RW /dev/ad4s1e" > /etc/gg.exports
  # ggated

On 192.168.0.20:

  # ggatec create -o rw 192.168.0.21 /dev/ad4s1e
  # gmirror label  data /dev/ad4s1e
  # gmirror insert data /dev/ggate0

and /etc/fstab becomes

# Device                Mountpoint      FStype  Options         Dump    Pass#
/dev/ad4s1b             none            swap    sw              0       0
/dev/ad4s1a             /               ufs     rw              1       1
/dev/ad4s1d             /usr            ufs     rw              2       2
/dev/mirror/data        /data           ufs     rw              2       2


-- 
Steve