Re: [libvirt] [PATCH v2] Add new attribute writeout to <filesystem> element
On 12/22/2011 11:07 PM, Daniel P. Berrange wrote:
On Thu, Dec 22, 2011 at 05:25:49PM +0100, Paolo Bonzini wrote:
> On 12/22/2011 03:20 PM, Eric Blake wrote:
>>>> Usage:
>>>> <filesystem type='mount' accessmode='passthrough'
writeout='immediate'>
>>>> <source dir='/export/to/guest'/>
>>>> <target dir='mount_tag'/>
>>>> </filesystem>
>> I still don't like the proposed XML. We need to get consensus on where
>> to put it, with my proposal being:
>>
>> <filesystem type='mount'>
>> <driver type='path' write='immediate'/>
>> <source dir='/export/to/guest'/>
>> <target dir='mount_tag'/>
>> </filesystem>
> Right, other types of drivers might include a userspace NFS client,
> or some kind of "artificial" filesystem.
>
> In addition, instead of write='immediate' I suggest
> cache='writeback'/cache='writethrough'.
Yeah I agree - we should follow the syntax we already use for caching
with the<disk> element instead of inventing new syntax
Daniel
Hi Dan and Paolo,
There had been a discussion earlier on the qemu-devel mailing list
on whether
cache=writethrough is appropriate for 9pfs Vs writeout as the attribute
name,
and it was decided to use writeout as the writeout behaviour is not
exactly what
cache=writethrough means. Ccing Aneesh here who was part of the original
qemu-devel discussion.
http://lists.gnu.org/archive/html/qemu-devel/2011-10/msg01274.html
Aneesh,
2 things being discussed here from 9pfs perspective
1) Whether writeout should be an attribute at the <filesystem...> level
or <driver..> level
in the XML schema.
2) Have cache=writethrough in the XML instead of writeout=immediate.
Comments pls.