A Multivendor Post to help our mutual iSCSI customers using VMware
Click for larger, more confusing view
Virtual Geek has an amazingly insightful post combining multiple presentations and points from representatives from EMC, MVWare, NetApp, Dell/Equalogic, HP/Lefthand, and some other folks in the business. As you can see by the names involved, we’re talking about most every major virtualization storage player in the industry today – and they’re here to help us make heads or tails of iSCSI storage. You’ll even be able to make sense of that diagram above after reading:
As discussed earlier, the ESX 3.x software initiator really only works on a single TCP connection for each target – so all traffic to a single iSCSI Target will use a single logical interface. Without extra design measures, it does limit the amount of IO available to each iSCSI target to roughly 120 – 160 MBs of read and write access.
This design does not limit the total amount of I/O bandwidth available to an ESX host configured with multiple GbE links for iSCSI traffic (or more generally VMKernel traffic) connecting to multiple datastores across multiple iSCSI targets, but does for a single iSCSI target without taking extra steps.
Here are the questions that customers usually ask themselves:
Question 1: How do I configure MPIO (in this case, VMware NMP) and my iSCSI targets and LUNs to get the most optimal use of my network infrastructure? How do I scale that up?
Question 2: If I have a single LUN that needs really high bandwidth – more than 160MBps and I can’t wait for the next major ESX version, how do I do that?
Question 3: Do I use the Software Initiator or the Hardware Initiator?
Question 4: Do I use Link Aggregation and if so, how?
Categorised as: Virtualization