In a nutshell, what we are about to do: we need to get the *files over onto your ESXi datastore where they can be accessible by the ESXi command-line esxupdate utility where we can then apply the latest ESXi 4.1 files as an update to our 4.0 installation.
First off, you need the newest release of the CLI install package from VMware, which can be freely downloaded here.
Having installed, I highly recommend a restart of the workstation you using the CLI on.
Running ESXi hosts on update 3b and having v Center Server on update 2 is normally a perfectly valid configuration but because SSLv3 got disabled as part of this process the connectivity is broken.
Example error messages in vpxd log file when patched host in being added to v Center Server include: ; cnx: (null), error: class Vmacore:: Ssl:: SSLException(SSL Exception: error:140000DB: SSL routines: SSL routines:short read) 2016-02-26T.729Z [07400 error 'httphttp Util' op ID=30D532A7-00000053-90] [Http Util:: Execute Request] Error in sending request - SSL Exception: error:140000DB: SSL routines: SSL routines:short read 2016-02-26T.730Z [07400 error 'vpxdvpxd Host Access' op ID=30D532A7-00000053-90] [Vpxd Host Access:: Connect] Failed to discover version: vim.fault.
VMware does not recommend re-enabling SSLv3 due to POODLE vulnerability.
If at all you need to enable SSLv3, you need to enable the SSLv3 protocol for all components. Now, there will be few scenarios where you cannot upgrade v Center Server to update 3b or you can’t do so even if its the recommended path and you simply want to have v Center update 2 working with ESXi update 3b hosts.
Http Fault Support for SSLv3 protocol is disabled by default.
In your v Sphere environment, you need to update v Center Server to v Center Server 5.5 Update 3b before updating ESXi to ESXi 5.5 Update 3b.
Now, if you are like me and need to perform an upgrade from ESXi 4.0 to ESXi 4.1 on an existing server, you may quickly find yourself a bit miffed at VMware for getting rid of the handy client-side GUI host-update-utility/server-update-utility that previously came with ESXi 4.0; instead, you will find yourself forced to work at the "unsupported" command-line within ESXi 4.1 for a bit, but do not fear, it is rather straightforward and worth the patience.
This step may sound a bit complicated or cumbersome to anyone that is used to doing all this sort of thing with nice little management GUIs, but it really is not TOO bad even for a novice.
On my system, some of the Perl related libraries the CLI depends on didn’t seem to work till I did a restart.