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-X 266 system interface or PCI Express™ (PCIe) system interface.
• Physical link (phy) speed of 3 Gbps SAS supporting transfer rates of 300 MB per second.
• 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).
• Some adapters support nonvolatile write cache.
• Support for RAID 0, 5, 6, and 10 disk arrays.
• 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, and 10 disk arrays
  • Ability to increase the capacity of an existing RAID 5 or 6 disk array by adding disks
  • Background parity checking
  • Background data scrubbing
  • Disks formatted to 528 bytes per sector, providing cyclical redundancy checking (CRC) and logically bad block checking
  • Optimized hardware for RAID 5 and 6 sequential write workloads
  • Optimized skip read/write disk support for transaction workloads
• Supports a maximum of 64 advanced function disks with a total device support maximum of 255 (the number of all physical SAS and SATA devices plus number of logical RAID disk arrays must be less than 255 per controller).