On 04/27/2011 03:27 PM, Stefan Hajnoczi wrote:
From: Anthony Liguori<aligu...@us.ibm.com>
When creating an image using qemu-img, just pass '-o copy_on_read' and then
whenever QED reads from a backing file, it will write the block to the QED
file after the read completes ensuring that you only fetch from the backing
device once.
This is very useful for streaming images over a slow connection.
While having the default in the file is sane, it seems to me that it
should be overridable at runtime, too.
Paolo
