Re: [SeaBIOS] [PATCH] fix two issues with virtio-blk

[Sebastian Herbszt]

Gleb Natapov wrote:
> On Sat, May 15, 2010 at 10:08:54PM +0200, Sebastian Herbszt wrote:
> > Why is a 4 KB physical sector size needed in a VM anyway?
>
> Performance of course. Qemu today can advertise physical block size and
> logical block size greater then 512 with virtio. The problem is that if
> logical block size != 512 boot fails.

Which OS currently has native support for 4 KB sectors and how big is the
performance gain? The performance without native support (emulation in
BIOS) could be worse due to the additional overhead. How much performance
is lost if the 512 byte logical sector size emulation is done in virtio (for reads
it could behave like a read ahead buffer) ?

Sebastian