[Kimchi-devel] [PATCH] bug fix: setup disks to use cache=none to support live migration.

[Royce Lv]

On 2014年03月05日 23:51, Paulo Vital wrote:
> When executing a virsh live migration of a VM created by Kimchi, the
> migration stops due to miss configuration "cache=none" on disk's
> performance parameters.
I'm little worried about make cache 'none' will cause performance 
downgrade for guest in daily running.
Can we allow update this parameter in vm disk edit and change it when we 
decide to live migrate a vm?
>
> Signed-off-by: Paulo Vital <pvital at linux.vnet.ibm.com>
> ---
>   src/kimchi/vmtemplate.py | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/src/kimchi/vmtemplate.py b/src/kimchi/vmtemplate.py
> index e2d78a4..89b5e72 100644
> --- a/src/kimchi/vmtemplate.py
> +++ b/src/kimchi/vmtemplate.py
> @@ -152,7 +152,7 @@ class VMTemplate(object):
>               params = {'src': src, 'dev': dev, 'bus': self.info['disk_bus']}
>               ret += """
>               <disk type='file' device='disk'>
> -              <driver name='qemu' type='qcow2'/>
> +              <driver name='qemu' type='qcow2' cache='none'/>
>                 <source file='%(src)s' />
>                 <target dev='%(dev)s' bus='%(bus)s' />
>               </disk>
> @@ -182,7 +182,7 @@ class VMTemplate(object):
>           # Passthrough configuration
>           disk_xml = """
>               <disk type='volume' device='lun'>
> -              <driver name='qemu' type='raw'/>
> +              <driver name='qemu' type='raw' cache='none'/>
>                 <source dev='%(src)s'/>
>                 <target dev='%(dev)s' bus='scsi'/>
>               </disk>"""