mirror without destroying existing contents

[Chuck Swiger]

On Mar 13, 2007, at 12:12 PM, Steve Franks wrote:
> Anyone made a mirror w/o destroying what's in the disk already?  The
> atacontrol man page is less than adequate in this respect...is is even
> possible?

Oh, yes-- it's certainly possible to create a mirror with live data,  
but one is advised to be cautious and have a full backup available in  
case of problems.  With hardware-based ATA controllers like Promise,  
3ware, etc, they should have a BIOS utility which you can use to  
create the mirror-- make sure to add the drive with valid data first,  
and then add the second or additional drives to the mirror set.

The same approach ought to work with software-mirroring such as (g) 
vinum.

-- 
-Chuck