On 06/05/2015 03:45, Fam Zheng wrote: >> > This is not enough, you also have to do the discard in block/mirror.c, >> > otherwise the destination image could even become fully provisioned! > I wasn't sure what if src and dest have different can_write_zeroes_with_unmap > value, but your argument is stronger. > > I will add discard in mirror. Besides that, do we need to compare the > can_write_zeroes_with_unmap?
Hmm, if can_write_zeroes_with_unmap is set, it's probably better to write zeroes instead of discarding, in case the guest is relying on it. Paolo
