HAST + ZFS self healing? Hot spares?

[Freddie Cash]

On Thu, May 19, 2011 at 4:25 PM, Pawel Jakub Dawidek <pjd at freebsd.org>wrote:

> On Thu, May 19, 2011 at 04:22:57PM -0700, Freddie Cash wrote:
> > With HAST, there's only a couple of small changes needed:
> >  - zpool offline poolname diskname        <-- removes the /dev/hast node
> > from the pool
> >  - hastctl role init diskname             <-- removes the /dev/hast node
> >  - remove dead disk
> >  - insert new disk
> >  - partition, label, etc as needed
> >  - hastctl role create diskname           <-- creates the hast resource
> >  - hastctl role primary diskname          <-- creates the new /dev/hast
> node
> >  - zpool replace poolname olddisk newdisk <-- adds the /dev/hast node to
> > pool
> >  - wait for resilver to complete
> >
> > The downside to this setup is that the data on the disk in the secondary
> > node is lost, as the resilver of the disk on the primary node recreates
> all
> > the data on the secondary node.  But, at least then you know the data is
> > good on both disks in the HAST resource.
>
> It shouldn't be the case. Primary HAST node should synchronize data from
> secondary HAST node, as primary has new disk. This should allow you to
> simply 'zpool online poolname disk' instead of replacing it.
> It doesn't work that way for you?
>

Oh?  Never thought to try that.  But, I guess that does make sense ... and
is the point of having the redundant data in the other server ...

Also, in my tests, I was running a degraded HAST setup (only 1 server), so
it wouldn't have been possible to do.

Will have to remember that for the next time I'm playing with HAST (the box
is currently a non-HAST setup).

-- 
Freddie Cash
fjwcash at gmail.com