Is it possible to get a list of extents mapped to an object from an ioctl call? The reason why I am asking is that I need to be able to calculate the deltas between a snapshot and a real device. For instance: Suppose I have a virtual machine on device /dev/lvmvol/vmserver. I create a snapshot of that device named /dev/lvmvol/vmsnap. If I could get a list of the extents used to constitute "vmserver" and the extents that constitute "vmsnap" I could calculate how much has changed and what ranges I need to actually backup. Obviously, there has to be some way to map "extents" to locations on the device itself in order for this to work. I have looked in the dm code and can not see if this is possible. Thanks, Mark -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
