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-X 266 system interface or PCI Express (PCIe) system interface.
• Physical link speed of 3 Gbps SAS that supports transfer rates of 300 MB per second.
• 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 multiported SAS devices.
• Embedded PowerPC® Reduced Instruction Set Computer (RISC) processor, hardware XOR Direct Memory Access engine, and hardware finite field multiplier (FFM) DMA engine for RAID 6.
• Some adapters that support nonvolatile write cache.
• Support for RAID 5 and RAID 6 disk arrays and system mirroring.
• 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 and 6 disk arrays and system mirroring.
  • 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-and-write disk support for transaction workloads.
• Supports a maximum of 64 advanced function disks with a maximum of 255 devices.
  Note: The number of all physical SAS and SATA devices plus the number of logical RAID disk arrays must be less than 255 per controller.