[libvirt] storage volume download/upload

As i see in some cases, for example in case of lvm storage pool libvirt spawns libvirt_iohelper to upload or download data to volume. But in case of big data contains zeroes this is wast bw of network. May be we can use gzip or lz4 for compression stream? How the best do this not breaking exiting software? May be add new parameter to libvirt_iohelper with compression method and compression level? In my cases of 20-160 Gb data and used only 4-5 Gb this provide major benefit.... Thanks! -- Vasiliy Tolstov, e-mail: v.tolstov(a)selfip.ru jabber: vase(a)selfip.ru