If the source image has dependence on other images, then we should use "qemu-img convert ", otherwise, "cp" is enough.
> -----Original Message----- > From: Marcus Sorensen [mailto:shadow...@gmail.com] > Sent: Wednesday, December 05, 2012 1:01 PM > To: cloudstack-dev@incubator.apache.org > Subject: Re: qemu-img convert a qcow2 to a qcow2 > > Eventually we'll probably want to support multiple versions, replacing one or > both of the formats with variables, but even then we'll probably just want to > copy if source format == destination format. > > > On Wed, Dec 5, 2012 at 1:51 PM, Rohit Yadav <rohit.ya...@citrix.com> > wrote: > > > > > On 05-Dec-2012, at 12:17 PM, Marcus Sorensen <shadow...@gmail.com> > wrote: > > > > > Anyone know why we do a convert from qcow2 to qcow2 when we crete > a > > volume > > > or template? It seems slower than file copy, and it strips valuable > > > compression which could speed up deployments significantly. Our > > > qcow2 templates are compressed to about 1/3 size of uncompressed, > > > and since the compression is read-only it doesn't really affect > > > future write > > performance, > > > and gives a slight performance gain to reads since less is read. > > > > > > createvolume.sh > > > qemu_img convert -f qcow2 -O qcow2 > > > > > > managesnapshot.sh > > > qemu_img convert -f qcow2 -O qcow2 > > > > > > createtmplt.sh > > > qemu_img convert -f qcow2 -O qcow2 > > > > > > I'd suggest if we already know it's qcow2, and we want to create a > > > qcow2 > > to > > > copy the file. Objections? > > > > > > I don't know why we do that, but what the command is saying is that we > > want to convert an input image from qcow2 to keeping the same output > > format, -O qcow2 But yes, if the input format is already qcow2 and > > output is qcow2 we can just copy the file. Edison? > > > > Regards.
