HP ProLiant AMD-based 300-series G7 servers

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For more information on the HP SAS Expander Card, go to
http://h18004.www1.hp.com/products/servers/pr
oliantstorage/arraycontrollers/sas-
expander/index.html.
SAS-2
SAS-2 and PCIe 2.0 are a
mong the technologies responsible for a significant increase in performance
over past generations of Smart Array controllers. The second-generation SAS (SAS-2) link speed
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of
6.0 Gb/s is double the SAS-1 transfer rate. Operation at SAS-2 link speeds requires SAS-2 compliant
hard drives. SAS-2 eliminates the distinction between fanout and edge expanders by replacing them
with self-configuring expanders. SAS-2 enables zoning for enhanced resource deployment, flexibility,
security, and data traffic management. SAS-2 is also backward compatible with SAS-1.
Beginning with HP product releases in the first quarter of 2009, Smart Array controllers are SAS-2
capable. In fully supported controllers, 6-Gb/s SAS technology allows Smart Array controllers to
deliver peak data bandwidth up to 600 MB/s per physical link in each direction. SAS devices are
capable of sending and receiving data simultaneously across each physical link (full duplex mode).
When running full duplex, 6-Gb/s SAS technology can deliver peak data bandwidth up to 1200
MB/s.
The SAS-2 specification is compatible with both Serial SCSI and Serial ATA protocols for
communicating commands to SAS and SATA devices. SAS-2 compliant controllers are fully
compatible with 1.5-Gb/s and 3.0-Gb/s SATA technology.
For the most up-to-date listing of HP Smart Array controllers that support the SAS-2 specification, see
the Smart Array controller matrix: www.hp.com/products/smartarray
.
HP Smart Array controllers based on PCIe 2.0
T
he Smart Array PCIe 2.0-based controllers are modular solutions with a common form factor,
hardware, and firmware. Any of the ProLiant 300-series G7 servers can use PCIe 2.0-based
controllers. As a standard entry level RAID, HP designed the Smart Array 410i with a unique Zero
Memory RAID (ZMR) capability. Administrators can choose the cache size and whether to include the
battery backed write cache (BBWC) or the flash-backed write-cache (FBWC). These options allow
users to upgrade from ZMR to 512 MB BBWC or 1GB FBWC.
Battery backed write cache
T
he BBWC system continues to be an option for capacity expansion (adding one or more physical
disks to an existing array). The Smart Array controller recalculates parity and balances the data
across all the disks. During the expansion, the BBWC preserves data and logical structures on the
array. The HP 650 mAh P-Series battery can power the cache for up to 48 hours before recharging
becomes necessary.
Flash-backed write cache
HP introduced
the flash-backed write-cache (FBWC) system in the fourth quarter of 2009. The FBWC
uses NAND
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flash devices to retain cache data and super-capacitors (Super-caps) instead of batteries
to provide power during a power loss. The FBWC offers significant advantages over the HP Battery-
backed write-cache (BBWC) system. Since the FBWC writes the contents of memory to flash devices,
there is no longer a 48-hour battery life limitation and the data will be posted to the disk drive on the
next power up.
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The Serial Attached SCSI - 2 (SAS-2 or SAS 2.0) is a draft standard, and is the product of the Technical Committee 10t
Organization. SAS 2.0 is second generation of SAS and is based upon SAS - 1.1. The SAS-2 specification is available from
the 10t website,
http://www.t10.org.
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Non-volatile semiconductor memory that can be electronically erased and reprogrammed. No power is needed to maintain
data stored in the chip