ESX isn't windows. Part of it is RedHat (the service console) but the VMkernel is almost as proprietary as ONTAP. The other 3 versions of VMware (Player, WS, and Server) all have version that run on Windows, but ESX is really it's own OS (with a lot of help from Linux).
ESX iSCSI does the authentication through the service console's IP/network but the actual I/O through the VMkernel. So, on the filer, you'll set two logins, one right after the other, from both IPs.
By default, VMkernel networking is not configured, and you need to set it up for iSCSI, NFS and VMotion. If you create a back end network for iSCSI, it will prompt you if the service console is not set up on that network. However, I've seen people change the networking (remove the service console from the back end after it was all up and running).
Here's what bit me: When you remove the SC from the back-end networking, existing iSCSI connections continue to work, until you reboot or otherwise disconnect. I installed a bunch of patches on a pair of ESX servers configured by somebody else. After I rebooted, iSCSI and all the VMs broke, and I spent several hours trying to figure out what I did to break it. When I disabled and re-enabled iSCSI, it complained about the svc console not being on the back end, and I spent the next 5 minutes smacking myself in the head for not thinking of it sooner.
So, one possibility here is that if they initially set it up with the SC on the back end, then removed it, any reconnect it does will be through the network the SC can see. That's a slightly educated guess.
Enjoy!
Peter
-----Original Message----- From: Blake Golliher [mailto:thelastman@gmail.com] Sent: Wednesday, March 14, 2007 2:38 PM To: Justin Brodley Cc: toasters@mathworks.com Subject: Re: ISCSI Issue and VMWare ESX 3.0.1
Why would the ESX server attempt to connect to the other interface unless it's a failover attempt? Is that what it's doing, trying to keep things going by going though this secondary network?
I'll freely admit windows isn't my forte.
-Blake
On 3/14/07, Justin Brodley jbrodley@sumtotalsystems.com wrote:
I'm currently dealing with a problem on several of our ESX IBM LS21 Blades when trying to attach to ISCSI Luns on the Netapp FAS 3020's. Our Netapp currently connects to two separate physical networks to deliver ISCSI connectivity. The ESX support folks are telling us that the netapp presents both ISCSI interfaces to the server. Initially the ESX box connects on the correct interface, but then after a few hours it attempts to try the other IP address and fails and disconnects the entire VM Host from the Netapp, despite the fact that the network never went down. We have several Windows 2003 servers with ISCSI initiator that don't have this problem on identical hardware and chassis.
I assume that either ESX's iscsi initiator is badly designed, or MS has broken some industry standard spec. To rearchitect our storage network will take significant investment on our part, and we'd rather come up with a way to fix this either by pushing on ESX to fix the initiator or finding a way to have the Netapp only send one IP address
back to the initiator. Is there any way to resolve this from the
Netapp perspective?
Thanks in advance.
-Justin