Re: [Qemu-devel] [PATCH] sheepdog: implement direct write semantics

[Paolo Bonzini]

Il 08/01/2013 13:12, Kevin Wolf ha scritto:
>> > Okay, I see the code indeed support WCE but it requires Guest kernel to
>> > support it. For the kernel doesn't support it, there is no way to
>> > disable write cache, no?
> With Linux guests, it's possible for SCSI. I'm not sure about
> virtio-blk, but you might be right that you can't manually change it there.

New enough kernels support it.  Also, if you reboot from a system that
supports writeback to one that doesn't (including old-enough Linux), the
new QEMU will be able to use writethrough while running on the older system.

Paolo