Re: What's the reasonable time to mirror a hard disk?
On Mon, 22 Oct 2001, Yuwen Dai wrote:
> Hi, All
> I have two identical hard disk linked with one cable. The capacity of each
> disk is 40G. I want to have the second disk be the mirror of the first disk
> by using this command:
> dd if=/dev/hda of=/dev/hdb bs=32k
> Nearly 2 hours passed, dd still hadn't finished. I had to press 'Ctrl-C' to
> stop it. Is this the right way to mirror a disk? Or is there some better
> way to do this? Thanks in advance.
After two hours, the best case is that you were transferring 6MB/sec,
which isn't too bad. It may have been *just* shy of finishing when you
cancelled it :(
Use hdparm to enable DMA on the disks and see if it speeds up. If you
don't know how to use hdparm, read its manual page (man hdparm).