I am having some fan issues on the C200. The fan is revving up randomly even with no load.
According to TAC the reason the fans are revving up randomly is because the firmware we have installed on the C200 M2 server does not support ESXi 5.1. TAC said to downgrade ESXi to 5.0 which is a support version for the highest level of firmware that we can install on the server.
According to UCS firmware support matrix 1.4(3u) is the highest firmware for C200 M2, which supports ESXi 5.0
Is there a way to downgrade ESXi to 5.0 without losing VMs? One of the VMs is a file server with 800 GB of files, which will take time to migrate to another machine.
Or more importantly is there a way to stop the fans from revving up? All logs do not report issues with fans.
How is your vmware host set up? Is it in a cluster with the VMs stored on the SAN? Where's the ESXi local disk?
If you're in a cluster this can only be done non disruptively if your VMs haven't had their hardware version upgraded. If your hardware version for the vms is 8 or higher you will not be able to non disruptively back your vm down, and I wouldn't recommended trying to manually image disks. It's far too risky, especially with instructions from me in a forum post. ;)
If the hardware version isn't 8 or later, you can put the host into maintenance mode, grab a cisco edition ESXi disk from VMware for 5.0, and reinstall ontop of the existing setup. Make sure to select the ESXi boot disk and not your VMFS san luns!!!
Once esxi is reinstalled, reconnect it in vcenter, reconfigure as necessary, move VMs back.
I would personally not bother. If the fans aren't causing an issue besides for noise just hang tight and do a firmware upgrade when possible. This is far more risky than getting the right firmware.