Customized Dell ESXi 5.0 image makes the 5.1 upgrade fail
When attempting to migrate a few hosts from ESXi 5.0 to 5.1 the update manager continuously failed. After a whole lot of searching and log combing I came across a Dell forum thread that shed some light on to the problem.
Unfortunately, Dell's updated ESXi image still failed. At this point I thought I would need to take a trip over to the data center and use a USB drive to upgrade the hosts. As I read through the thread, I came across a solution by Harri T (page 5, second to last post).
In essence, use VMWare's depot to patch the 5.0 install via SSH.
Download VMware-ESXi-5.1.0-799733-depot.zip and copy it to a local datastore.
Download tg3-3.124c.v50.1-841079.zip and extract tg3-3.124c.v50.1-offline_bundle-841079.zip to a local datastore. I'm not sure if this is needed because depot.zip above has tg3 already.
Enter Maintenance mode.
Enable SSH, log in and type:
esxcli software profile install -d /vmfs/volumes/DATASTORE_NAME/VMware-ESXi-5.1.0-799733-depot.zip -p ESXi-5.1.0-799733-standard --ok-to-remove
reboot
exit
After rebooting exit Maintenance mode and disable SSH.