Le Monday 20 Aug 2012 à 12:24:33 (+0100), Stefan Hajnoczi a écrit : > On Mon, Aug 20, 2012 at 12:23 PM, Stefan Hajnoczi <stefa...@gmail.com> wrote: > > On Mon, Aug 20, 2012 at 11:12 AM, Benoît Canet <benoit.ca...@irqsave.net> > > wrote: > >> Le Tuesday 14 Aug 2012 à 16:14:02 (+0200), Benoît Canet a écrit : > >>> This patchset create a block driver implementing a quorum using m qemu > >>> disk > >>> images. Writes are mirrored on the m files. > >>> For the reading part the m files are read at the same time and a vote is > >>> done to determine if a qiov version is present n or more times. It then > >>> return > >>> this majority version to the upper layers. > >>> When i < n versions of the data are returned by the lower layer the > >>> quorum is broken and the read return -EIO. > >>> > >>> The goal of this patchset is to be turned in a QEMU block filter living > >>> just > >>> above raw-*.c and below qcow2/qed when the required infrastructure will > >>> be done. > >>> > >>> Main use of this feature will be people using NFS appliances which can be > >>> subjected to bitflip errors. > >>> > >>> This patchset can be used to replace blkverify and the out of tree > >>> blkmirror. > >>> > >>> usage: -drive > >>> file=quorum:n/m:image_1.raw:...:image_m.raw,if=virtio,cache=none > >> > >> stefanha: I am wondering what would be needed to do in order to have COR > >> and streaming working > >> with quorum.c ? > > > > .bdrv_is_allocated()/.bdrv_co_is_allocated() needs to be supported by > > block/quorum.c. Have you tried it and found a problem? > > Just want to confirm you are thinking about image streaming on top of > quorum? Or are you thinking about streaming underneath quorum?
I am thinking about streaming with quorum on top of a bunch of backing files. ie: data landing into the higher level backing file living just under quorum. Benoît > > Stefan
