# Kvm driver : loosen qemu-kvm -M option

**URL:** <https://forum.opennebula.io/t/kvm-driver-loosen-qemu-kvm-m-option/970>\
**Category:** Product Support\
**Created:** [July 7, 2015, 10:59am UTC](https://forum.opennebula.io/t/kvm-driver-loosen-qemu-kvm-m-option/970 "2015-07-07T10:59:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ssesubs](https://avatars.discourse-cdn.com/v4/letter/s/65b543/32.png) [@ssesubs](https://forum.opennebula.io/u/ssesubs)\
**Post date:** [July 7, 2015, 10:59am UTC](https://forum.opennebula.io/t/kvm-driver-loosen-qemu-kvm-m-option/970/1 "2015-07-07T10:59:26Z")

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Hello,

I am not able to migrate from hypervisor A to hypervisor B but I can from B to A … servers are the same hardware, under centos, the only difference is that A is centos 6.5 and B is centos 6.6. I have compared everything to my knowledge and that’s the only difference I can find.

On machine A: /usr/libexec/qemu-kvm -M ?  
Supported machines are:  
pc RHEL 6.5.0 PC (alias of rhel6.5.0)  
rhel6.5.0 RHEL 6.5.0 PC (default)  
rhel6.4.0 RHEL 6.4.0 PC  
…

On machine B:  
/usr/libexec/qemu-kvm -M ?  
Supported machines are:  
pc RHEL 6.6.0 PC (alias of rhel6.6.0)  
rhel6.6.0 RHEL 6.6.0 PC (default)  
rhel6.5.0 RHEL 6.5.0 PC  
rhel6.4.0 RHEL 6.4.0 PC  
…  
Is there any way to 'edit machine A to add rhel6.6 or to force qemu-kvm to accept any machine?