Intel AXXROMBSASMR, Hardware User'S Manual

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4 Intel® Integrated RAID Module SROMBSASMR Hardware User’s Guide
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Auto-detection of failed drives with transparent rebuild. There must be disk activity
(I/O to the drive) for a missing drive to be marked as failed.
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Auto-resume of initialization or rebuild on reboot (the Auto Rebuild feature must be
enabled before virtual disk creation).
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Smart initialization automatically checks consistency of virtual disks if there are five
or more disks in a RAID 5 array, which optimizes performance by enabling read-
modify-write mode. RAID 5 arrays of only three or four drives use Peer Read mode.
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Smart Technology predicts failures of drives and electronic components.
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Patrol Read checks drives and maps bad sectors.
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Commands are retried at least four times.
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Firmware provides best effort to recognize an error and recover if possible.
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Failures are logged from controller and drive firmware, and SMART monitor.
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Failures are logged in NVRAM, viewable from OS Event Log, Intel
®
RAID Web
Console 2, CIM, and LEDs.
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Multiple cache options allow configuration-specific performance optimization:
— Write-back: Faster because it does not wait for the disk but data will be lost if
power is lost.
— Write-through: Usually slower but ensures data is on the disk.
— Read Ahead: Predicts next read will be sequential and buffers this data into the
cache.
— Non Read Ahead: Always reads from the drive after determining exact location
of each read.
— Adaptive Read Ahead: Reads ahead and caches data only if doing sequential
reads.
— I/O setting. Determines whether read operations check the cache before reading
from disks.
✧
Cache I/O: Checks cache first, only reads disk if data is not in the cache.
✧
Direct I/O: Reads data directly from disk. (not cache)
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Redundancy through:
— Configuration stored in non-volatile RAM and on the drives (COD).
— Hot-swap support.
— Optional battery backup for cache memory.
SAS/SATA Features
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Provides four independent PHYs, each supporting 3.0 Gbps SAS and SATA data
transfers.
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Scalable interface that supports up to 16 physical devices and 64 logical devices via
expanders.