ISCSI sloooow Connection issues with NX4

Question

Hi,

We just purchased a NX4, 15K drives. EMCconfigured everything for us. We also bought three HP DL380 G7s and I have installed ESXion each. I have configure ISCSI using Hardware initiatior. I confgiured 4 ports for ISCSI (Rondrobin) connection and setup them up based on VMware recommendation (2 NICs with failover). So I have 4 connections to the SAN. I am able to see the LUNS on Vcenter. But, I beleive I am getting slow performace. I can create 1GB file in about 35 seconds and I think, this is very very slow. The switches are configured as 1GB on each port. Here are my questions:

1- Is there any tools avaiable for me to test to see how fast is MB per second I am getting on hard drives

2- Is there anything I can do on the switch side to increase performace (I have broadcomm, so jojumbo frames)

4- What kind of test I can run to see how fast are the dirves?

3- Basically how I increase performace.

Thanks

Valley911 · Answer

dst2000,

For testing your disk performance I would recommend using IOMeter. It is a free application to download and to run from a Windows based VM. There is a lot of great information out there about using this tool and testing storage with VMware. Just fire up google and you should be able to find something, also I would recommend checking out this thread on the VMware forums "Unofficial Storage Peformance Thread". There they have a template to use with IOMeter and you can gauge your performance along with others that have posted in the thread. http://communities.vmware.com/message/584154

Also I would download and read through the latest "iSCSi SAN Configuration Guide" from the VMware documentation site as there maybe helpful information in there (I am not that familiar with hardware initiators). Regarding the use of Jumbo Frames, from the testing I have done and from what I have read from bloggers is that there is not major increase in actual performance per say when using Jumbo Frames, but there is better utilization of your networking gear (meaning less processor utilization on the switches).

Hope these tips help out,

-Jason

rsamples · Answer

what type of Hardware iSCSI are you using, i know in 4.1 they enabled TOE support on allot of braodcom cards, but it seams to still have issues. allot of folks on the vmware forum suggest using the Software iSCSI bound to one of the NICs you were using hardware iscsi.

it seams to make a huge improvement.

there are plenty of guides they can walk you thru setting up the sw iSCSI.

yes i know TOE should be better but so far it's not...

dst2000 · Answer

Hi Robert,

We are using Broadcom NC382i iSCSI Adapter.

I have to talk to VMWare and they helped me configure the hardware iSCSI

but they never suggested or recommended to you both.

I am not very clear of using both software iSCSI and hardware iSCSI, are

you saying I can use BOTH at the same time?

Thanks.

VMware

ISCSI sloooow Connection issues with NX4

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