On 1/8/2017 5:18 PM, Anton Nefedov wrote:
This pull request is to address a few performance problems of qcow2 format: 1. non cluster-aligned write requests (to unallocated clusters) explicitly pad data with zeroes if there is no backing data. This can be avoided and the whole clusters are preallocated and zeroed in a single efficient write_zeroes() operation, also providing better host file continuity 2. moreover, efficient write_zeroes() operation can be used to preallocate space megabytes ahead which gives noticeable improvement on some storage types (e.g. distributed storages where space allocation operation is expensive)
ping? I'd send the rebased series but there are no real conflicts so /thanks, Anton