clear metadata using dd?

[Rick C. Petty]

On Fri, Jan 26, 2007 at 08:54:30PM +0100, Pawel Jakub Dawidek wrote:
> On Fri, Jan 26, 2007 at 01:14:14PM -0600, Rick C. Petty wrote:
> > On Fri, Jan 26, 2007 at 05:57:23AM -0800, R. B. Riddick wrote:
> > However, I'm not a big fan of the priority placed on the I/O to sync the
> > disks.  Pretty much during a resync, the box is unusable for file/disk I/O
> > for a number of hours.  Apps using GNOME/GTK are almost non-responsive, and
> > forget about even using java/eclipse.  I haven't found a good way to tune
> > gmirror's sync. [...]
> 
> Have you tried setting kern.geom.mirror.sync_requests to 1?

I've fiddled with all of kern.geom.mirror.* knobs.  I have no idea what
these knobs do (although I've made educated guesses), and the man page is
quite lacking.

> > [...] I also wish you could pause the sync, restart, and unpause
> > it where it left off. [...]
> 
> It should just work. When you reboot during the sync process it should
> continue after the reboot from the place it stopped.

I have *never* seen this behavior, and I have restarted mid-sync a number
of times.  After each time, "gmirror status" reports 0% complete.  I've
tried this on 5.4, 5.5, 6.0, 6.1, but not 6.2 yet.

-- Rick C. Petty