[sheepdog-users] sheepdog replication got stuck

[Liu Yuan]

On Tue, Jan 07, 2014 at 07:31:18AM +0100, Gerald Richter - ECOS wrote:
> Hi Liu,
> 
> thanks for your feedback. I will try the test you mentioned later on, when the recovery has finished.
> 
> Just one question, my understanding was, that the sheep daemon is flushing the cache after some time on it's own. Is there something like this or is the cache only flushed when a sync comes from the VM?
> 

Yes, we have a background flusher which will be triggered if more than 10
objects(40MB) are dirty periodically. But you have dirty data less than 40M,
no background flusher will be triggered and it can only be flushed by VM's
proactive flush requests from VM's filesystem or 'sync|fsync' from user space.

I think of adding yet another background flusher, which is triggered by time
interval, e.g, 30s once a time to flush any dirty objects. This will workaround
buggy QEMU problem.

Thanks
Yuan