I want to roll back from 3.5 to 3.0.2 on my test system that has a heap of VM's on ISCSI storage. (software iscsi target)
From memory the last time i rebuilt my esx server (and selected keep VMFS partition) i still had to format it to get the partition back, Is there a way i can rebuild ESX and add back in the same VMFS storage without the new build needing to format it and loose all my VM's ?
Just do a full new install. Your new install hasn't got iSCSI enabled default, so you only will have a local vmfs. You need to add the iSCSI Service Console and VMkernel, than rescan and you will see the datastore... If you have the access to the iSCSI LUN setup correctly that is.
My virtualisation blog:
i assume you are reinstalling v302 from scratch. When you are doing this should cause no harm to your VMFS on the iSCSI volume because you can´t touch it until the installation is complete.
As you already know , ISCSI SW adapter init, rescan and then you should see your VMFS volume.
(Assumtion that it hasnt been formated with 3.5.x, because i don´t know if 3.0.x can read VMFS-3.31 http://which is the version when you format it with 3.5.x, and v3.0.x has VMFS-3.21)
Keeping VMFS partitions only works afaik for partitions which are visible during installation (FC, local).
ps: Award points if you find answers helpful. Thanks.