Re: cloning a drive with dd

[Herb Peyerl <hpeyerl%beer.org@localhost>]

On 24-Jun-08, at 8:10 AM, Al - image hosting services wrote:

> I am setting up a server for a local Habitat for Humanity. The  
> server has
> 2 drives and I was going to use the second drive as a backup. Then  
> I got
> an idea, why not build the kernel with root on wd0a and clone the  
> drive?
> If the first drive was to fail, then the second drive should work as a
> stand alone. I found an example, but it wasn't from a NetBSD site.  
> I was
> going to boot from the live cd and use:
>
> dd if=/dev/wd0d of=/dev/wd1d bs=32k conv=noerror,sync
>
> But from what I remember it was really easy to trash both hard  
> drives with
> this and was wondering if this is the best way to do it.

I don't think it's generally recommended but you're certainly not  
going to trash the source hard drive... Not sure where that piece of  
FUD comes from.

In the past I've used rsync to backup root drives to backup drives...  
You need to installboot on the second drive seperately and then -- 
exclude /boot... You can decide whether to use --delete... i've  
always chosen to not use --delete just in case something goes nuts  
and starts deleting files on my primary disk... Then I do --delete  
manually occasionally...