Upgrade from ESX 4.1 to ESXi 4.1 U1?

[mcvosi]

Is this doable, or should I do a clean install?

[Troy_Clavell · Accepted solution]

there is no upgrade path from classic ESX to ESXi.  So, a clean install is your only option.

[DSTAVERT]

If you have local disks for VMs it is possible to install ESXi directly to USB flash stick. ESXi will recognize the local datastore. You will need to reconfigure Networking, Switches etc and add the existing VMs to inventory but works well and very quick.

[RR9]

you can't upgrade  esx to esxi .. if you are having VMs stored on datastore on SAN the its easy...

you unpresent the LUNs to this server and then install esxi4.1 U1 ... after this present the LUN and rescan storage....