To scan for updates
esxupdate -m https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/esx/vmw/vmw-ESXi-4.1.0-metadata.zip scan
Stage updates
esxupdate -m https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/esx/vmw/vmw-ESXi-4.1.0-metadata.zip stage
Enter Maintenance Mode
vim-cmd /hostsvc/maintenance_mode_enter
Apply updates
esxupdate -m https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/esx/vmw/vmw-ESXi-4.1.0-metadata.zip update
Exit Maintenance Mode
vim-cmd /hostsvc/maintenance_mode_exit
Finally Reboot
reboot
