Every time I go to install VMware on a Cisco UCS C-Series server,
I seem to forget something or come across a new caveat. If this sounds
familiar, read these tech tips for configuring UCS with VMware vSphere.
- Local storage: If you’re going to connect to a SAN on the
backend and you’re using VMware, you usually don’t need to purchase
extra local hard drives. You can purchase Flexible Flash, which is
basically a proprietary Cisco SD card that comes with a partition on
which the hypervisor can be installed. Purchasing extra hard drives can
cost more, and they might never be utilized.
- Boot order: You should go into the Cisco UCS Integrated
Management Controller (CIMC) and configure the BIOS boot order. After
installation, you’ll want your hard drive to boot first. On the UCS
server, they usually default to PXE booting. The nice thing about this
is you don’t need to restart the server to get into the BIOS and do this
configuration; if you configure it from the CIMC, it will give you a
message that it won’t take place until after a restart. The next time it
restarts, though, it will boot in the proper order you set up (most
likely, hard drive first).
- vSphere installation: You need to use the Cisco customized .iso file to install ESXi
on your UCS servers; the file has built-in drivers specific to the
servers. Also, you want to make sure you’re using the most recent
version. I made the mistake of using one I had that was a couple months
old; when I installed it, I couldn’t see all of my NICs — it turned out
I was missing drivers for the onboard card. When I tried the newest
.iso file, it worked like a charm. In addition, make sure you enable the
HV drive before trying the install, or else you’ll just need to start over again.
- Network adapters: If you’re adding a network card, make sure
you enable it before installing vSphere. You can enable it after the
physical installation by going into the CIMC, clicking Inventory, and
then clicking the Network Adapters tab. Record the slot ID there, and
then click BIOS while still in the CIMC. Click the Advanced tab and
ensure the option ROM for that slot ID is enabled. (Note: If you ordered
extra local storage, you’ll do the same thing for the PCIe SCSI
If you have tech tips you’d like to share on this topic, please post them in the discussion.
Also read my article: Installing vSphere on Cisco UCS C-Series servers