[DRBD-user] drbd & multicast?

[Volodymyr Litovka]

Adam,

On 07.04.2020 02:52, Adam Goryachev wrote:
>>
>> From what I see I conclude, that in 1st case (originator is "disk"
>> node) the single copy of replicated data travels through network,
>> while in 2nd case (originator is "diskless" node) there are two
>> copies travel through network.
>>
>
> I guess the "solution" is to increase the available bandwidth between
> the diskless node, and your "SAN". One option is using multiple
> ethernet connections bonded or dedicated to each destination (eg, one
> ethernet to stor2, one ethernet for stor3, and a third ethernet for
> the "user" network).
>
> Or, use faster ethernet such as 10G ethernet connections to improve
> the performance.
>
Partially agree with you. From bandwidth side, 25G Ethernet will solve
this question, while 25G LACP will solve it forever :-) But multicast
approach can reduce number of packets, which need to be processed by
originating host and transit network. Again, more powerful CPUs and
Ethernet offload will do the job, but all these tricks is yet another
brute force way.

Nevertheless, this issue neither serious problem nor problem at all.
Being new to DRBD, I asked this question just to clarify things.

Thank you.

--

Volodymyr Litovka
   "Vision without Execution is Hallucination." -- Thomas Edison