On Thu, Jun 20, 2013 at 04:59:17PM +0800, Wenchao Xia wrote: If I understand correctly, you have a backing chain with internal snapshots:
> imageA(sn0)->imageB(sn0,sn1)->imageC(sn0) And you want to convert this to a chain of external snapshots: > imageA_sn0.qcow2-->imageA.qcow2-->imageB_sn0.qcow2-->imageB_sn1.qcow2- > ->imageB.qcow2-->imageC_sn0.qcow2-->imageC.qcow2 You also want each image file to contain only data that is not in the parent. So imageA.qcow2 would not contain identical clusters from imageA_sn0.qcow2. The most efficient way of doing this is by looking into the L1/L2 tables of the imageA(sn0) and imageA so that you know which clusters are different. This is a weird operation. It also has a dual, converting the external snapshot chain into a chain of image files with internal snapshots - again sharing clusters instead of duplicating them. It's possible to implement this but I'm a little surprised that anyone would want to do this. And I wonder if management tools can cope with this mix of internal and external snapshots :). Stefan
