Fresh install on gmirror'ed disks?

Freddie Cash fcash at
Tue Mar 7 17:04:11 UTC 2006

On Tue, March 7, 2006 4:39 am, JoaoBR wrote:
> On Tuesday 07 March 2006 08:55, Volker wrote:
>> I do agree that gmirror is not that bad and not that difficult. But
>>  take a look at how to setup a fresh system using gmirror (slice by
>>  slice mirroring):
>> - install a complete system to a fresh disc
>> - create the (well sized) slices on a 2nd disc (not that easy)
>> - create the gmirror set on disc 2
>> - bring gmirror up
>> - copy all filesystems over to the gmirror set
>> - reboot
>> - create exactly sized slices on disc 1
>> - insert everything into the gmirror set
>> Using that procedure you're going to copy each installed file three
>>  times (install, copy to mirror, sync mirror). That's a waste of
>> time compared to a solution where the installer would be able to
>> install directly into a mirror.

There's no need to copy files around.  gmirror handles it all for you
behind the scenes.  Just create the gmirror labels using the existing
disks/slices/partitions, then insert the second set of
disks/slices/parittions.  gmirror will handle synchonising the data
across the mirror.

>> When using disc based gmirror (instead of per slice gmirror) the
>> procedure is a bit easier, but similar.

> there is no need to copy anything around ...
> - you do install the system as usual
> - before rebooting you create the to be mirrored disk with the gmirror
> label command (you do not loose data here)
> - then you change your fstab acordingly
> - you reboot
> - you insert the mirror disk(s)
> - gmirror should start syncing automatically if you did everything
> right

> realy, this is a 3 minute thing

This is the process I just went through.  It would be nice if there
was a post-install step that did this automatically, but it wasn't all
that hard to do manually.  Just CTRL+F4 to open the terminal, run a
few commands to create the mirror, edit /etc/fstab, and exit the

Dru Lavigne's OnLamp article about this makes it almost trivial to do.

Freddie Cash
fcash at

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