We have been using EX4500 and EX4200 switches for several years. To upgrade Junos on these switches we have been:
We have a new EX4600 in production and after a bit of research it seems like I should add the force-host as shown below
request system software add /var/tmp/<NameOfPackage.tgz> force-host
Should I be adding the force-host at the end?
What exactly does the force-host do?
The EX4600 is a virtualized system, so it runs a host operating system with JunOS as a virtual machine. The 'force-host' option will upgrade the underlying host OS as well as the JunOS VM. It is not necessary to upgrade the host during every software upgrade, and the host and JunOS versions do not have to match. I believe the version release notes will indicate if a host OS upgrade is required for that version. Otherwise it is optional, and there should be no operational impact if the host is upgraded or not.