IBM SAS RAID controllers, Manual

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SAS RAID controllers for IBM i
This topic provides usage and maintenance information regarding the SAS RAID controllers for IBM i.
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:
v
PCI-X 266 system interface or PCI Express (PCIe) system interface.
v
Physical link speed of 3 Gbps SAS that supports transfer rates of 300 MB per second on PCI-X and
PCIe adapters.
v
Physical link speed of 6 Gbps SAS supporting transfer rates of 600 MB per second on PCIe2 and PCIe3
adapters.
v Support for SAS devices and nondisk Serial Advanced Technology Attachment (SATA) devices.
v
Optimized for SAS disk configurations that use dual paths through dual expanders for redundancy
and reliability.
v
Controller managed path redundancy and path switching for SAS devices with multiple ports.
v
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.
v
Support nonvolatile write cache for RAID disk arrays on some adapters (PCIe2 and PCIe3 adapters
feature Flash-Backed-DRAM which eliminates the need for rechargeable batteries).
v
Support for RAID 5 and RAID 6 disk arrays and system mirroring.
v
Support for attachment of other devices such as non-RAID disks, tape, and optical devices.
v RAID disk arrays and non-RAID devices supported as a bootable device.
v
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.
Note: This feature is not suggested for PCIe2 and higher adapters due to performance
considerations.
– Background parity checking.
– Background data scrubbing.
– Disks formatted to 528 bytes per sector, providing cyclical redundancy checking (CRC) and logically
bad-block checking on PCI-X and PCIe controllers.
– Disks formatted to 528 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-and-write disk support for transaction workloads.
v
Supports a maximum of 64 advanced function disks with a maximum of 255 devices on PCI-X and
PCIe controllers.
v
Supports a maximum of 240 advanced function disks with a maximum of 1023 devices on PCIe2 and
PCIe3 controllers.
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