replacing harddisks

Manolis Kiagias sonicy at
Thu Jul 2 17:54:10 UTC 2009

pepe wrote:
> I have gmirror of two 200GB disks where I have whole /usr f my freebsd 7.2
> system. root, /var and /boot are on other disk, but I need to replace those
> both disks with bigger ones now. To get bigger /usr. So what I'm wondering
> now is if there is way to take one disk out of mirror (geom) and add bigger.
> So it would be one 200g and one 640g.

If you add the 640G in the 200G mirror, it will be used as a 200G.

>  And after sync replace other 200g with
> 640g so there would be two 640g disks. What I don't know is if mirror would
> still be original 200g or can I get it working full 640g this way? Or do I
> need to do it some harder way? Like adding both disks, creating mirror of
> them, copy original mirror with dd to new one and then removing old disks?

There are probably a couple of way to achieve this, but I would add the
new disk as a standalone one, copy (rather dump) contents from the array
to it, disconnect the older array, create a gmirror on the new disk, and
finally connect the second new disk and resync.  You don't need to add
both new disks at the same time (you may not even have enough sata
connectors) and you don't even have to leave both of the original mirror
disks connected while copying the data.  It will still work the same if
the original array is degraded.

More information about the freebsd-questions mailing list