Hello Richard,
One more question, you mentioned that "hot plugging" is supported from CentOS 7 and gave me a link. That link says

 "In libguestfs ≥ 1.20, you may add drives and remove after calling"guestfs_launch". There are some restrictions, see below. This is calledhotplugging."

When I executed "sudo yum install libguestfs-tools" on CentOS 6.5, it installed libguestfs 1.20.11. So if we fix the current qemu issue  then can we use "hotplugging" in CentOS 6.5? Do you see some other issues? Do you recommend CentOS 7 only for the "hotplugging"?

Many Thanks for all your help.

On Thu, Sep 18, 2014 at 5:51 AM, Priyanka Ranjan <priyanka3rdfeb@gmail.com> wrote:
Thanks Richard,
I have asked CentOS and qemu mailing list about this issue and waiting for their reply. 

 It is really strange that on CentOS 6.4 VM, atleast qemu was wokring but  in higher version "6.5" it is not working.

On Wed, Sep 17, 2014 at 8:57 PM, Richard W.M. Jones <rjones@redhat.com> wrote:
On Wed, Sep 17, 2014 at 08:52:57PM +0530, Priyanka Ranjan wrote:
> Many Thanks Richard for your reply.
> #  /usr/libexec/qemu-kvm -nographic -machine accel=kvm:tcg -device \?
> open /dev/kvm: No such file or directory
> failed to initialize KVM: Operation not permitted
> Back to tcg accelerator.
> Could not allocate dynamic translator buffer
> I tried executing "setsebool -P virt_use_execmem=on" also after looking at
>  "http://libguestfs.org/guestfs-faq.1.html"  but that also did not help.
> Please guide me how to fix this issue and proceed further.

That command is the way you're supposed to fix this problem.  If it
doesn't work then I don't know -- perhaps ask on a CentOS or qemu list,
or open a bug against CentOS?


Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
Fedora Windows cross-compiler. Compile Windows programs, test, and
build Windows installers. Over 100 libraries supported.