So you have one or more esxi boxes at home doing various tasks and they are currently running esxi 4, your tempted to update to 4.1 but do not have update manager installed and do not want the hassle of configuring esxi again.
No Problem good old command line to the rescue again. To upgrade 4 to 4.1 you need the esxi 4.1 upgrade installation as a zip file and the vcli (vsphere command line interface) both are available from the vmware site (I wont post links as I dont know how quickly the links will age), Once you have downloaded the VCLI and installed it you will have a new program item in your startprogramsvmware folder called “vmware Vclicommand prompt”. Click on that and it will dump you in the the old familiar black and white screen. Ensure any vm’s on the server are either powered off or migrated and put the host into maintenance mode.
Navigate your way to the “bin” directory (currently “c:program filesvmwarevsphere clibin” on my computer and run the following:
“vihostupdate.pl –server 0.0.0.0 –install –bundle c:zipfilelocation”
Press return and enter the esxi servers admin credentials (probably the root account in a home environment.) in a few minutes the command will complete and tell you that it needs to reboot the server before the process finishes, do this and when it comes back up exit maintenance mode.
WARNING: Before updating be sure to have consulted the vmware HCL (hardware compatibility list) to ensure that your server is compatible with the version you are trying to install. If your server is not specifically listed then you can check out the individual components compatibility either through the hcl or the community driven hcl. the hcl is currently located HERE