iSCSI Transfer Speed Question

[CoreyWilson]

We are running an ax150 iscsi san and I notice that on my 2003 and 2000 servers that are connected at 1gpbs to the san through a 1gbps switch and using cat6 cable that when transferring a single static file of say 4+gb the network usage as displayed in task manager for the 1gpbs network card never exceeds 50%.

Does this indicate that somewhere between the server’s 1gig network card and the SAN the traffic is being dropped to 100mbps? The file still transfers at a rate much quicker then it does if I manually force the connection speed to 100mb so I would think the actual speed IS running at 1gbps.

Is this just a short coming with windows or am I doing something wrong?

Thanks

 

[mbourne2006]

Hi Corey

What other components are involved in the transfer? 50% of 1Gb/s is equivalent to 64MB/s by my rough & ready calculations - is there another component in the device chain somewhere that might be throttling things back?

HTH

Kind Regards,
Matthew Bourne
"Find a job you love and never do a day's work in your life.

 

[CoreyWilson]

Not to my knowledge, no. Basically my servers connect from their 1gbps nic's using cat6 to 1gbps switches which then connects to the SAN using cat6. In essence everything should be running at 1gbps. I am not sure if somehow something is throttling the speed back but my network conneciton in windows shows as connected at 1gbps which would make me think that its atleast getting to the switch at 1gpbs.

The switches are Dell PowerConnect 2724's.

I am going try tonight when traffic dies down connecting a server directly to the SAN and see what happens with the transfer speeds then.

 

[CoreyWilson]

I had an opportunity to review these settings. Everything is connected at and running at 1000mbps. However in windows 2003 task manager | network tab the max it will ever display is network throughput of 50%.

Is this a bug or limitation in the software?

Thanks

 

[CoreyWilson]

resolved the issue. it had to do with the fact that we did not have the SNP hotfix from Microsoft installed to our server images.