iSCSI vNIC a requirement?

[Lewis Benton]

If I'm not intending to boot from an iSCSI array, do I need to go the extra step and configure iSCSI vNIC's for use within vSphere or am I safe with just creating standard vNic's with the appropriate settings for Jumbo Frames, etc...?

I believe before UCS 2.0 that was sufficient, but from talking with TAC it sounds like the iSCSI vNIC is now mandatory with vSphere..

Is there any added benefit to creating iSCSI vNIC's (beyond booting from an iSCSI array.)

Thanks in advance,

Lewis Benton

[lwatta · Accepted solution]

iSCSI vNICs are only required if you are going to do iSCSI boot.

If you are not doing iSCSI boot you do not need an iSCSI vNIC in your service profile.

If you want jumbo frames set it on the vNIC and make sure to also set it on the QOS policy

louis

[Robert Burns]

Just to add to Louis, the iSCSI vNIC creates a hardware initiator within the host (required for iSCSI boot).  For post-boot iSCSI access you can use the built-in vSphere software iSCSI initiator which just binds to the parent vmknic & vNIC interface.

When configuring your jumbo frames, ensure you test ping with a jumbo packet to ensure efficient transport.  Many times there's a switch or interface that's missed which renders a jumbo MTU inefficient.

Scott Lowe put together a create article on Jumbo frames w/ VMware.  It's drafted against vSphere 4, but still applies to vSphere 5.

http://blog.scottlowe.org/2009/05/21/vmware-vsphere-vds-vmkernel-ports-and-jumbo-frames/

Regards,

Robert

[Lewis Benton]

Thanks a lot.  I thought that would be the case, but the response I got from TAC suggested otherwise.  If the only purpose of them is for iSCSI boot then I'll stick with standard vNIC's.

[lwatta]

If you could send us the Case number so we can look into it.

thanks

louis