Patch esxi 5.0 using cli

Put the host in maintenace mode :
vicfg-hostops –server 10.10.10.10 –operation enter

To verify which VIBs are already installed on the ESXi 5 host, issue the following command:

esxcli –server=10.10.10.10 –username=root software vib list | more

To update the ESXi 5 host with the VIBs included in the depot, issue the following command:
esxcli –server=10.10.10.10 –username=root software vib update –depot=/vmfs/volumes/datastore1/ESXi500-201109001.zip
vicfg-hostops –server 10.10.10.10 –operation reboot

Update 5.1 to 5.1U1

esxcli software vib install -d /vmfs/volumes/datastore1/update-from-esxi5.1-5.1_update01.zip