FreeBSD 9/ZFS: Striped Pool (2 disks) migrating to mirror (onto additional disk)

Dan Nelson dnelson at allantgroup.com
Wed Jan 26 22:00:48 UTC 2011


In the last episode (Jan 26), Christer Solskogen said:
> On Wed, Jan 26, 2011 at 9:42 PM, Dan Nelson <dnelson at allantgroup.com> wrote:
> > ZFS lets you add and detach mirrors on the fly, since you're not
> > changing the capacity of the pool itself.   Sure, you're going to lose
> > the contents of the large 2TB drive, but that's sort of assumed.   You
> > can't convert 4TB of non-mirrored disks into 2TB of mirrored disks
> > without losing 2TB of space.  Just make sure you have less than 2TB
> > total used data on all volumes, and copy the data off the 2TB filessytem
> > onto the striped 1+1TB one before repartitioning and adding the mirrors.
> >
> >  zpool attach [-f] pool device new_device
> 
> The problem is that you cant attach a drive to a vdev that consists of two
> striped disks.

We may have to defer back to Oliver to see exactly how his disks are set up
("zpool status pool1" and "pool2" would be nice), but if he did two "zpool
add" commands, he has two independant vdevs in one zpool, and he can mirror
each of them with a "zpool attach" command.  ZFS doesn't have a "stripe"
vdev type.

-- 
	Dan Nelson
	dnelson at allantgroup.com


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