[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] Effect of qemu-img convert -m and -W options

From: Richard W.M. Jones
Subject: Re: [Qemu-devel] Effect of qemu-img convert -m and -W options
Date: Thu, 16 Nov 2017 15:12:33 +0000
User-agent: Mutt/1.5.20 (2009-12-10)

On Thu, Nov 16, 2017 at 03:51:29PM +0100, Peter Lieven wrote:
> Afaik all writes to the same QCOW2 serialize because of the s->lock that
> is held during the write. So its not suprising that there is no benefit from
> mutliple threads as long as reading from the RAW file involves no delay.
> Which is likely due to readahead of the OS.

I guess this would explain it, thanks.


Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.

reply via email to

[Prev in Thread] Current Thread [Next in Thread]