On 04/18/2013 03:37 PM, Stefan Hajnoczi wrote:
>> @@ -184,6 +186,8 @@ typedef struct SheepdogInode {
>> > uint32_t data_vdi_id[MAX_DATA_OBJS];
>> > } SheepdogInode;
>> >
>> > +static bool discard_supported = true;
> Normally state should be part of BDRVSheepdogState so that it does not
> affect other sheepdog drives.
>
> Please confirm that all -drive file=sheepdog:... must either support
> discard or not support it. I asked this in an older version of the
> patch but wasn't sure if my question was clear.
>
Ah, I see, this time I got your question clearly.
> Imagine a scenario where you run two sheepdog clusters and want to
> connect one drive from each cluster to your VM. If one cluster uses
> outdated sheepdog software but the other is up-to-date, then it should
> still be possible to use discard on the up-to-date cluster.
Makes sense. I'll use a per structure enabler.
Thanks,
Yuan
