Limiting factors for iSCSI SW HBA / only 100MB in VM

[alex123]

Hi everybody,

first i try to explain my problem.

We configured an iSCSI Target with SLES10.3. We can write (20GB) from another Server to that Target over NW with eg. 400MB/s. Using the iSCSI Target.

Now we configure our ESX Server to use this Target as HBA. Create a VM on an NFS Storage, create a hard disk on this Target. Now we repeat the writettest. We're not able to get more than 100MB/s.

Why? Can we change something? If its normal, which element decrease the speed?

I spent much time to find a solution for this problem. But i find4 nothing helpful.

HW Config:

ESX Server (ESX 3.5 build 153875):

HP DL 380 G8, 32 GB RAM, 8 x 2,833GHz, NW 2 x 10Gbit Ports with CX4.

Storageserver:

No Name Server / 8 x 500GB Raid 0 / NW 2 x 10Gbit Ports with CX4.

Thanks for helping, if you need more infos, write short info.

[drummonds]

3.5 only supports 1Gb/s traffic on the VMkernel network ports (iSCSI and NFS). If you want to fully utilize a 10 Gb/s link, you need to update to ESX 4.0.

Scott

More information on my communities blog and on Twitter:

http://communities.vmware.com/blogs/drummonds

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[alex123]

Thanks for your hint. Can i find this information in datasheets from vmware or in other sheets?!

I search 2h and don't find anything. Thanks!