SAS RAID controllers for IBM i

Find usage and maintenance information regarding controllers for the serial-attached SCSI (SAS) Redundant Array of Independent Disks (RAID) for IBM® i. Use this information with your specific system unit and operating system documentation. General information is intended for all users of this product. Service information is intended for a service representative trained on the system unit and the subsystem being serviced.

The SAS RAID controllers for IBM i have the following features:

  • PCI Express (PCIe) system interface.
  • Physical link speed of 6 Gbps SAS supporting transfer rates of 600 MB per second on PCIe3 adapters.
  • Support for SAS devices and nondisk Serial Advanced Technology Attachment (SATA) devices.
  • Optimized for SAS disk configurations that use dual paths through dual expanders for redundancy and reliability.
  • Controller managed path redundancy and path switching for SAS devices with multiple ports.
  • Embedded PowerPC® Reduced Instruction Set Computer (RISC) processor, hardware XOR Direct Memory Access (DMA) engine, and hardware finite field multiplier (FFM) DMA engine for RAID 6.
  • Support nonvolatile write cache for RAID disk arrays on some adapters (PCIe3 adapters feature Flash-Backed-DRAM which eliminates the need for rechargeable batteries).
  • Support for RAID 5, RAID 6, and RAID 10 disk arrays and system mirroring.
  • Support for attachment of other devices such as non-RAID disks, tape, and optical devices.
  • RAID disk arrays and non-RAID devices supported as a bootable device.
  • Advanced RAID features:
    • Hot spares for RAID 5, 6, and 10 disk arrays and system mirroring.
    • Background parity checking.
    • Background data scrubbing.
    • Disks formatted to 528 or 4224 bytes per sector, providing SCSI T10 standardized data integrity fields along with logically bad block checking on PCIe3 controllers.
    • Optimized hardware for RAID 5 and 6 sequential write workloads.
    • Optimized skip read-and-write disk support for transaction workloads.
  • Supports a maximum of 240 advanced function disks with a maximum of 1023 devices on PCIe3 controllers.