[sheepdog-users] Many vdi snapshots may block the network

[Liu Yuan]

On Mon, Dec 09, 2013 at 04:26:49PM +0100, Valerio Pachera wrote:
> Hi, I was doing a stress test on my testing cluster: a cylcle that creates
> a snapshot for each one of my vdi and then remove them.
> 
> While the script was running may colleagues complained about frozen
> Internet connection.
> As soon as the script stopped, they also stopped complaining.
> 
> I tried again to run the script, and the connection went off.
> 
> Does the action of taking snapshot generate lots of broadcast?
> May this be related to corosync more than sheepdog?

Yes, snapshoting makes cluster drivers(corosync, zk) generate broadcast, several
broadcast per snapshot. The real number is diterminzed by the underlying driver,
but I guess corosync will generate much more traffic than zk.

Thanks
Yuan