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how to change the location of qemu-kvm emulator [closed]

asked 2017-02-02 05:43:55 -0500

chkrishn gravatar image

updated 2017-02-03 07:30:52 -0500


I have installed openstack Mitaka on RHEL 7.3. The default version of qemu-kvm that comes with the OS is 1.5.3. But i need a version of 2.6.0 for my provisioning to work. I have installed it in a non-default location of /usr/local/bin. The default location of qemu that is getting picked is /usr/libexec/qemu-kvm.

What changes/settings are required to be made so that my provisioning picks the qemu from /usr/local/bin/qemu-system-x86_64?

Is there any parameter for emulator that can be mentioned?

Please let me know of any suggestions.

I am seeing the below message in nova-compute log

2017-02-03 08:08:10.345 20441 ERROR nova.compute.manager [instance: 1340ecee-bdd5-4488-a26f-4ce122005684] libvirtError: internal error: process exited while connecting to monitor: 2017-02-03T13:08:06.480275Z qemu-kvm: -drive file=/dev/disk/by-path/,format=raw,if=none,id=drive-virtio-disk0,serial=2bce82fc-9c71-45e1-90ae-268638148982,cache=directsync,aio=native: aio=native was specified, but is not supported in this build.

Thanks Krishna

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Closed for the following reason the question is answered, right answer was accepted by chkrishn
close date 2017-02-08 04:59:03.191622

2 answers

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answered 2017-02-04 10:44:20 -0500

sgordon gravatar image

updated 2017-02-04 10:44:41 -0500

The CentOS Virtualization Special Interest Group (SIG) provides qemu-kvm-ev-2.6.0 builds, including dependencies, in this repository:

Alternatively subscribers to Red Hat OpenStack Platform and Red Hat Enterprise Virtualization will find qemu-kvm-rhev-2.6.0 in the base repositories for those offerings.

I would recommend installing whichever of the above you are able to access, everything should "just work". It will replace the base qemu-kvm package and be called in its place. No symlinks etc. required.

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Thanks for the suggestion. I installed 2.6.0 version but I am still seeing the same error

 ./qemu-kvm --version
QEMU emulator version 2.6.0, Copyright (c) 2003-2008 Fabrice Bellard
chkrishn gravatar imagechkrishn ( 2017-02-05 23:07:58 -0500 )edit

answered 2017-02-02 05:54:28 -0500

volenbovsky gravatar image

updated 2017-02-06 05:56:33 -0500

Hi, maybe creating symbolic link would be the easiest?

UPDATED answer, to address 'aio=native: aio=native was specified, but is not supported in this build.': It sounds that you are hit by change in QEMU 2.6 "Specifying block device parameter aio=native is now an error on POSIX systems if qemu is compiled without libaio support. The newly invalid combination had been warning since QEMU 2.3." So maybe QEMU was compiled without libaio support.

Some possible way forward: -most likely Nova chooses aio=native instead of aio=threads which is default because of You can try to remove the if conditions to 'bypass' that -compile QEMU yourself or try to convert Debian package into rpm (using 'alien' - hmm, don't really know if it works out)

Bug reports to CentOS/Redhat and/or OpenStack might be good to have in case situation is like this.

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Thanks for the suggestion. Sorry for the late reply. My system crashed and i had to rebuild from scratch. I made the softlink but it did not solve the issue. My VM provisioning is going to ERROR state.

chkrishn gravatar imagechkrishn ( 2017-02-03 07:17:47 -0500 )edit

I updated the question with additional information of the message that i am seeing in nova-compute log

chkrishn gravatar imagechkrishn ( 2017-02-03 07:31:26 -0500 )edit

Thanks a lot. I downgraded my qemu to 2.3 version and I am able to provision the VMs. "The newly invalid combination had been warning since QEMU 2.3." This line helped me to decide on downgrading my QEMU.

chkrishn gravatar imagechkrishn ( 2017-02-08 04:58:38 -0500 )edit

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Asked: 2017-02-02 05:43:55 -0500

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Last updated: Feb 06 '17