Re: [Libguestfs] [PATCH nbdkit] filters: Add copy-on-write filter.

On Sat, Jan 20, 2018 at 04:58:43PM +0000, Richard W.M. Jones wrote: I should add that if the use of SEEK_DATA etc proves too adventurous, it wouldn't be much trouble to modify this to use a simple block bitmap. With a 4K block size the bitmap is 1/32768th of the size of the disk, so even a 1 TB disk only needs a 32 MB bitmap which can comfortably be kept in memory. But it seemed a shame to do that when the operating system is essentially maintaining equivalent state. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/