Re: [Qemu-devel] 'qemu-nbd' explicite flush to disk

[Mark Trumpold]

Paolo,

Awesome!!!  I just tried your patch, and it works beautifully.
I've been struggling with the lack of '--cache=writeback' for
months now with many work-arounds/kludges.

Thank you again for responding.
Qemu rocks!

Best regards,
Mark Trumpold



> -----Original Message-----
> From: Paolo Bonzini [mailto:address@hidden On Behalf Of Paolo
> Bonzini
> Sent: Wednesday, September 12, 2012 11:30 PM
> To: Mark Trumpold
> Cc: address@hidden
> Subject: Re: 'qemu-nbd' explicite flush to disk
>
> Il 12/09/2012 23:28, Mark Trumpold ha scritto:
> > So, I've been experimenting with 'qemu-nbd --cache=writeback ..'
> > This nicely eliminates the 'checkpoint' issue; however, I have as
> > yet been unable to explicitely flush things to disk -- which I would like to
> > do just before a 'nilfs' snapshot.
>
> The Linux kernel driver for NBD does not support flushes.  Patches were
> sent to the maintainer, but he never applied them.
>
> You can get them at
> http://thread.gmane.org/gmane.linux.drivers.nbd.general/1108 and try
> them.
>
> > Subsequently I've been trying to call 'bdrv_co_flush(bs)' directly, but I 
> > can't
> figure out how to dereference 'bs' for the call.
> >
> > I'm probably out in the weeds on this one.
> > Any guidance would be greatly appreciated.
> >
> > I am running:
> >     qemu-1.2.0
> >     linux kernel 3.3.1
> >
> > Thank you,
> > Mark Trumpold
> >
> >
> > Confidentiality Notice: The information contained in this electronic
> > e-mail and any accompanying attachment(s) is intended only for the use
> > of the intended recipient and is confidential and/or privileged.
>
> I doubt so, since this is a public mailing list.
>
> Paolo


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