David Laight <david@l8s.co.uk>  wrote:
 > On Tue, Dec 10, 2002 at 08:05:17AM -0600, Frederick Bruckman wrote:
 > > On NetBSD, the whole (first) disk is "/dev/wd0d", the third is
 > > "/dev/wd2d".
 > > 
 > > One warning: sometimes when you try to write past the end, the kernel
 > > spews messages, then downgrades the DMA mode, which is inconvenient.
 > > The work-around is to calculate and supply the exact "count" to "dd"
 > > for a given "bs".



note, 'd' only represents the whole 'disk' on i386 port (possibly others
like hpcarm and shark?) and on others it's 'c'. 

Also, if you're dd'ing, you probably want to use the raw devices and
supply a bs=32k or bs=64k to dd... 

frankly, unless the disks are identical in geometry and size, I probably
wouldn't use 'dd' to mirror them.