iSCSI initiator could not send PDU after upgrade to ESX4

[bgoodman]

I just upgraded one of my ESX hosts from 3.5 to 4. I have migrated a couple of VMs back and they are working fine. Here is the problem. When I migrate a Windows Server 2008 machine that is using the Microsoft iSCSI Initiator to connect directly to the SAN, the VM will migrate and run but it begins moving very slowly. It has 2 iSCSI connections to the SAN and only 1 will work. The other starts throwing EventID 7 "The initiator could not send an iSCSI PDU". I have a couple of VMs like this and both of the ones I tried to migrate do the same thing. If I migrate them back to the other host still running 3.5 they start working fine again. This problem only happens when I migrate a VM to version 4.

I have looked at the Microsoft iSCSI Initiator in the VM and the networking settings in ESX4 and compared them to the 3.5 host and all seems to be fine.

What am I missing?

Thanks,

Brad

[admin]

Did you know that answers to many technical issues can be found by searching our Knowledge Base at http://kb.vmware.com ?

Rick Blythe

Social Media Specialist

VMware Inc.

[bgoodman]

Actually, I searched the KB and read through all 127 articles related to "iscsi" and all articles for a couple other searches and couldn't find anything that really helped. What I ended up having to do was this:

1. End the sessions in the Microsoft iSCSI Initiator and tell it to not reconnect them on the next reboot. Then reboot.

2. Manually uninstall the VMware Tools and reboot again.

3. Install the new version of VMware Tools and let it reboot.

4. Run the Hardware Upgrade and let it reboot again.

5. Reconnect new, persistent connections in the Microsoft iSCSI Initiator. Made sure I had access to the RDMs. Then rebooted again to double check and make sure there were no errors.