Abstract: A data storage system and method thereof to access a raid volume in pre-boot environment are provided. The data storage system may include a processor, a memory coupled to the processor, a host controller interface coupled to the processor, and a plurality of storage devices coupled to the host controller interface, the plurality of storage devices including a respective plurality of Option Read Only Memories (ROMs). The processor may be configured to execute a system code loaded from one of the plurality of Option ROMs to cause the processor perform operations comprising forming a Redundant Array of Independent Disks (RAID) volume from at least two of the plurality of storage devices.