Wednesday, August 6, 2014

configuring the LSI MegaRaid 9271 for VMware vSAN

Those configuring the LSI 9271 can take heart – you don't have to configure each disk by hand for VMware vSAN. 

The problem – The only controller that Cisco sells that is also on the VMware HCL for vSAN is the LSI MegaRaid 9271. VMware vSAN recommends pass-through mode (JBOD). LSI does not support this. In this case, VMware supports creating virtual disks for each physical disk, of type RAID0. 
The solution I originally tried was to use the StorCli software, made by LSI and found on the UCS Utilities disk for C series. It installs directly in the ESXi shell as a VIB. 
BUT, creating individual disks required an individual command for each disk, i.e. 

/opt/lsi/storcli/storcli  /c0 add vd type-RAID0 name=vd1 drives=32:1
/opt/lsi/storcli/storcli /c0 add vd type=RAID0 name=vd2 drives=32:2
Even worse, the enclosure number was required for each command (shown in the above example as ’32’). Since enclosures are potentially different for each server, this made scripting difficult, as finding the enclusre number added complication. 

The solution – As it turns out, someone at LSI was thinking about this problem. They must have faced this particular use-case before (where customers want each pd to have a RAID 0 vd). So the put in a one line command to handle this situation: 

cd /opt/lsi/storcli
./storcli /c0 add vd each type=raid0 pdcache=off  

UPDATE: some commands removed as they did not work in latest testing. 

This command quickly builds all the virtual disks on the physical disks. No muss. No fuss. The extra commands turn off all the caching done by the controller. vSAN likes to take care of this itself. I haven't tested it for performance yet, so this may change in the future.