This seems like it should be trivial information to find, however I can't seem to get a definiative answer for it online. I want to do a fresh intstall of ESXi 5.0. Currently the host has network switch & portgroups on it. I would prefer to use the vicfg-cfgbackup command to export the config so I don't have to recreate this information. Can I use this backup for an import onto the new ESXi 5.0 host? We are currently running ESXi 4.1.
The contents of the backup files have change sufficiently that I don't think the vCLI would allow you to force a restore over the new host. You could force restores between different patch levels with ESXi 4, but I would think it would fail restoring to ESXi 5.
You might consider a script like this to export / import your config - http://www.virtu-al.net/2009/06/27/powercli-easy-vswitch-portgroup-setup/ or if you're licensed for vCenter / EntPlus you could use host profiles to reconfigure the new host.