Re: [Drbd-dev] switching between protocols A and C

[Lars Ellenberg <lars.ellenberg@linbit.com>]

On Wed, Apr 11, 2007 at 02:46:02PM +0100, Cristian Zamfir wrote:
> Lars Ellenberg wrote:
> >On Wed, Apr 11, 2007 at 01:13:32PM +0100, Cristian Zamfir wrote:
> >>Hi,
> >>
> >>Would it be possible to switch from protocol A to C and vice versa 
> >>without disconnecting (for instance detach, switch protocol and 
> >>re-attach)?
> >>
> >>This would be useful when alternating between two primaries (only 
> >>protocol C can be used) and a primary/secondary configuration where 
> >>protocol A may increase write throughput on the primary node.
> >
> >protocol A does _NOT_ increase throughput at all.
> >it _MAY_ reduce latency somewhat sometimes.
> 
> I am testing with the bonnie++ benchmark over a 100Mbps link and I get a 
> substantial increase for output in the case of protocol A at the expense 
> of higher CPU ratio. From what I understand, it would make sense to get 
> better throughput from the asynchronous protocol over low quality links. 
> Or am I doing something wrong?

and your exact bonnie++ command line is:

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