Multipathing in VMware kills connection to datastores
Posted on 2014-09-26
Hello Experts - I recently upgraded to ESX/Vcenter 5.1 and I'm trying to add a second NIC to my iSCSI vswitch in VMware. Whenever I enable the second NIC within five minutes I lose connectivity to three of my six datastores. My environment consists of three ESX 5.1 hosts, Vcenter 5.1, a Netapp FAS2240-4 SAN, and an HP 2920 switch. After speaking with support engineers from both companies I believe the problem relates to load balancing. I have not been able to determine the answer to certain questions:
1) Which SATP software should VMware be using to connect to the Netapp? Right now its showing up as VMW_SATP_DEFAULT_AA which I am told is generic software when VMware doesn't know what kind of SAN is on the other end.
2) Is the FAS2240-4 able to use ALUA (I don't believe it is capable)
3) What Load Balancing method should I be using and where should it be set?
For number three I have been told different things by different techs Initially we configured the VMware datastores to use round robin and also set the ifgroups on the Netapp to use round robin but I was told that this should only be set on the VMware side, not the Netapp. The Netapp tech that assisted in the initial setup seemed to think both the Netapp and Datastores needed to be setup to use round robin so that is how we did it. As much as I'd like to just try disabling load balancing on the Netapp it appears that the ifgroups can't be modified once they are created...true?
I've got so much conflicting info here that I'd like to try and get a consensus on what the actual best practices are for my particular configuration. I'd really appreciate any advice on how to get this going. I've been through 4 VMware techs so far without any resolution.