This depends on what storage controller you have on the server. If you have a PERC controller you can create RAID 10 virtual disk on the PERC controller. If you have software RAID controller then you need to change SATA setting to RAID mode and you can create RAID 10 under S140 controller BIOS.
If installing esxi 7.3 on a Poweredge, in the Bios - SATA settings do I setup a raid there or leave it as AHCI mode ? I do want to setup a raid 10 just not sure  if is done when i create the datastore in esxi or if I set the raid at the bios level  
PowerEdge R340 -Raid and ESXI