Am 28.08.2017 um 04:57 hat Fam Zheng geschrieben: > On Fri, 08/25 15:44, Max Reitz wrote: > > Well, OK. The main argument against supporting anything but qcow2 is > > "if you want features, use qcow2; and we are working on making qcow2 as > > fast as possible." I think that's a very good argument still. At some > > point I (and probably others, too) had the idea of making qcow2 files in > > raw layout: > > Yes! I think this idea makes a whole lot of sense, too. Metadata tables can be > generated so old implementation can still use it.
Maybe a nice way to attack this would be "huge pages", i.e. have a L1 entry flag that tells "this points directly to a huge cluster instead of an L2 table". Gives us 512 MB clusters with a 64k cluster size, or a maximum of 512 GB clusters with a 2 MB cluster size. Huge clusters would only be used by qemu-img create if the respective option is given, and only with preallocation. Kevin
