On Tue, Mar 10, 2015 at 11:51:15AM +0300, Denis V. Lunev wrote: > From the point of guest each write to real disk prior to disk barrier > operation could be lost. Therefore there is no problem that "not synced" > new block is lost due to not updated allocation table if QEMU is crashed. > This situation is properly detected and handled now using inuse magic > and in parallels_check > > This patch improves writing performance of > qemu-img create -f parallels -o cluster_size=64k ./1.hds 64G > qemu-io -f parallels -c "write -P 0x11 0 1024k" 1.hds > from 45 Mb/sec to 160 Mb/sec on my SSD disk. The gain on rotational media > is much more sufficient, from 800 Kb/sec to 45 Mb/sec. > > Signed-off-by: Denis V. Lunev <d...@openvz.org> > CC: Roman Kagan <rka...@parallels.com> > CC: Kevin Wolf <kw...@redhat.com> > CC: Stefan Hajnoczi <stefa...@redhat.com> > --- > block/parallels.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Roman Kagan <rka...@parallels.com> Roman.
