SAS RAID controllers for AIX overview

Find usage and maintenance information regarding controllers for the serial-attached SCSI (SAS) Redundant Array of Independent Disks (RAID) for the AIX® operating system. Use this information in conjunction 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 specifically trained on the system unit and subsystem being serviced.

The SAS RAID controllers for AIX have the following features:

  • PCI Express (PCIe) system interface.
  • Physical link (phy) speed of 3 Gbps SAS supporting transfer rates of 300 MB per second on PCIe controllers.
  • Physical link (phy) speed of 6 Gbps SAS supporting transfer rates of 600 MB per second on PCI Express 3.0 (PCIe3) controllers.
  • Supports SAS devices and non-disk 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 multiported SAS devices.
  • Embedded PowerPC® RISC Processor, hardware XOR DMA Engine, and hardware Finite Field Multiplier (FFM) DMA Engine (for Redundant Array of Independent Disks (RAID) 6).
  • Support nonvolatile write cache for RAID disk arrays on some adapters (PCIe3 controllers feature Flash-Backed-DRAM which eliminates the need for rechargeable batteries).
  • Support for RAID 0, 5, 6, and 10 disk arrays on PCIe3 controllers.
  • Support for RAID 5T2, 6T2, and 10T2 Easy Tier® disk arrays on selected PCIe3 controllers.
  • Supports 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, 10, 5T2, 6T2, and 10T2 disk arrays
    • 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 PCIe2 and PCIe3 controllers
    • Optimized hardware for RAID 5 and 6 sequential write workloads
    • Optimized skip read/write disk support for transaction workloads
  • Supports a maximum of 240 advanced function disks with a total device support maximum of 1023 (the number of all physical SAS and SATA devices plus the number of logical RAID disk arrays must be less than 1023 per controller) on PCIe3 controllers.