A few colleagues of mine recently worked with a customer deploying VMware Virtual SAN (VSAN) with Cisco UCS hosts using the LSI MegaRAID 9271CV-81 I/O Controller and documented the configuration choices below. Note, in general the VSAN guidance has been to disable all controller cache so these choices follow this theme. Also note that we are not LSI experts and would welcome feedback from others on their experience with other settings.

Change the default settings in the screenshot below to the following:

  • Access = RW
  • I/O = Direct
  • Read = Disable
  • Disk Cache = Disabled
  • Disable BGI = No
  • Default Write = Write Through

LSI MegaRAID BIOS Config 01

* All settings can be changed on the fly or using storcli for VMware:

http://www.lsi.com/downloads/Public/RAID%2520Controllers/RAID%2520Controllers%2520Common%2520Files/1.09.13_StorCLI.zip 

* User guide

http://www.lsi.com/downloads/Public/RAID%20Controllers/RAID%20Controllers%20Common%20Files/51530-00_Rev_L.zip

Other versions of the MegaRAID controller might have a screen that looks something like the one below:

LSI MegaRAID BIOS Config 02

Thanks to my colleagues Justin Beck and Jason Burroughs for documenting and sharing their experience.