Re: [Qemu-discuss] Disk Performance

[dw+qemu-discuss]

On Fri, May 30, 2014 at 06:47:15PM +0200, Stephan von Krawczynski wrote:

> > I'm no expert on this, but it sounds to me like the file copy is using
> > memory to cache disk blocks, swapping out the memory that is the
> > emulated memory of the guests.  It seems to me that the solution to
> > that is to force the Qemu process's memory space to remain in RAM.
> > 
> > Is there a way to do that in Linux?
> 
> No.

Unrelated to solving the original problem, just wanted to point out this
is in fact trivially possible, and there have been patches in the past
to implement it.

See http://lists.gnu.org/archive/html/qemu-devel/2012-09/msg05081.html
and http://linux.die.net/man/2/mlockall


David