Am 18.06.2013 um 05:03 hat Wenchao Xia geschrieben: > Hi, Kevin > In normal case, qcow2 is based on raw-posix file which don't support > discard operation
It does, see raw_aio_discard(). > , so this serial doesn't change much in this case, > still real space is not freed in snapshot delete, and it completes > fast. Instead, tt affects the case that some protocol below support > discard, so delete will be more clean but slower in that case. Is this > true? Maybe add this in commit message? Yes, it becomes a little bit slower, but not much in my tests. Kevin