[iSCSI] Trying to reach max disk throughput

[Ben RUBSON]

> On 10 Aug 2016, at 13:44, Edward Tomasz Napierała <trasz at FreeBSD.org> wrote:
> 
> On 0810T1154, Ben RUBSON wrote:
>> Hello,
>> 
>> I'm facing something strange with iSCSI, I can't manage to reach the expected disk throughput using one (read or write) thread.
> 
> [..]
> 
>> ### Initiator : iscsi disk throughput :
>> 
>> ## dd if=/dev/da8 of=/dev/null bs=$((128*1024)) count=81920
>> 10737418240 bytes transferred in 34.731815 secs (309152234 bytes/sec) - 295MB/s
>> 
>> With 2 parallel dd jobs : 345MB/s
>> With 4 parallel dd jobs : 502MB/s
>> 
>> 
>> 
>> ### Questions :
>> 
>> Why such a difference ?
>> Where are the 167MB/s (462-295) lost ?
> 
> Network delays, I suppose.

I just saw that iSER is available in FreeBSD 11, let's install BETA4 and give it a try.