Yesterday I was at the New England VTUG event which is always a great event to meet up with familiar faces and be introduced to some new ones. I met up with a relatively new VMware Virtual SAN customer and we discussed lots of fun things about VSAN and their implementation experience. One frustrating thing they mentioned is that they couldn’t find anywhere that documented how to put the Cisco 12G SAS Modular Raid Controller in Pass-Through mode. They explained that after lots of searching on VMware and Cisco’s site, they contacted Cisco and were provided the information. They were kind enough to capture a screenshot of the setting and provide it to me.

The procedure is:

  • Log into the Cisco UCS Manager
  • Open a console to the host
  • Reboot the host
  • On boot up hit Ctrl+R to enter the Cisco 12G SAS Modular Raid Controller BIOS Configuration Utility
  • Hit Ctrl-N until the “Ctrl Mgmt” page is selected
  • In the bottom right hand corner, make sure the “Enable JBOD” field shows an X per the screen shot below.
  • Hit Ctrl-S to save Reboot

Cisco 12G SAS Enable JBOD

That’s it. Easy.

If this is a brand new, unconfigured host, the unclaimed disks in the host will now get passed to ESXi and VSAN can use them for the VSAN datastore.

However, if this host IO Controller had previously been configured with RAID, you should check out: How to delete the RAID configuration from drives managed by the Cisco 12G SAS Modular Raid Controller

I hope that helps others save some time in getting VSAN up and running.

Special thanks to Stephanie Forde and Matthew Gabrick from the Boston Water and Sewer Commission for pointing this out and providing the screenshot.