About performance tuning of jsnbd openbmc

[Jeremy Kerr]

Hi Xiuzhi,

[CCing the openbmc list, as this is relevant]

> Hi Jeremy,
>    I am trying to  install Centos7.iso image by openbmc nbd-server.
> The performance is too slow to install the OS image . The speed is no
> more than 40KBytes/s. My network speed is 1000Mbps.
>   The speed is up to 512KBytes/s when the openbmc nbd-client connect
> to the  nbd-server of nbd3.19 which running on my ubuntu 16.04 PC.
>   What factors affect the transmission speed?
>  How can I improve the speed of nbdserver?
>   The attachments is patch to webui and phosphor-handler and
> nginx.conf(I user nginx as the webserver instead of the  bmcweb)


I see your client-side javascript includes this:

+                server.onlog = function(msg) {
+                    $scope.nbdslog += msg + "\n";
+                }

- I've found that the logging like that (appending to an increasingly-
large string) can cause fairly large slowdowns.

Could you try removing this and see if that improves the speed?

Cheers,


Jeremy