I/O technologies. HP ML150 - ProLiant - G6

If an uncorrectable error occurs, the system automatically directs the read to the mirrored location to obtain the correct data. Since each mirrored DIMM is one of a pair, one DIMM can be protected by mirroring while another is degraded. As a result, even after mirroring is degraded by a DIMM failure, the other DIMM in the mirrored pair is still protected by Advanced ECC. The OS does not revert to

Advanced ECC Mode until the failed DIMM is replaced and the server rebooted.

Memory channel interleaving

Xeon 3400, 5500, and 5600 Series processors retrieve data from the memory DIMMs in 64-byte chunks. With channel interleaving, the system is set up so that each consecutive 64-byte chunk in the memory map is physically transferred by means of alternate routing through the three available data channels.

The result is that when the memory controller needs to access a block of logically contiguous memory, the requests are distributed more evenly across the three channels rather than potentially stacking up in the request queue of a single channel. This alternate routing decreases memory access latency and increases performance. However, interleaving memory channels increases the probability that more

DIMMs need to be kept in an active state (requiring more power) since the memory controller alternates between channels and between DIMMs. This is discussed further in the “Power and thermal technologies” section.

Lockstep memory mode

Lockstep mode is an advanced memory protection feature supported in ProLiant Intel 100-series G6 servers using the Xeon 5500 and 5600 Series processors. It uses two of the processor's three memory channels to provide an even higher level of protection than Advanced ECC. In lockstep mode, two channels operate as a single channel—each write and read operation moves a data word two channels wide. The cache line is split across both channels to provide 2x 8-bit error detection and 8bit error correction within a single DRAM. In three-channel memory systems, the third channel is unused and left unpopulated. The Lockstep Memory mode is the most reliable memory protection method, but it reduces the total system memory capacity by a third in most systems. Performance is measurably slower than normal Advanced ECC mode, and uncorrectable memory errors can only be isolated to a pair of DIMMs instead of a single DIMM. Lockstep mode is not the default operation; administrators must enable it in BSU.

For additional information about DDR3 memory, see the technology brief titled “Memory technology evolution: an overview of system memory technologies” at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00256987/c00256987.pdf.

NOTE:

Memory mirroring with DDR3 and Lockstep memory mode are not supported on the

DL1000 Multi Node server

I/O technologies

ProLiant 100-series G6 servers incorporate PCI Express, Serial-Attached SCSI (SAS), and Serial ATA

(SATA) I/O technologies. PCI Express lets administrators add expansion cards with various capabilities to the system. SAS is a serial communication protocol for direct-attached storage devices such as SAS and SATA hard drives.

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PCI Express technology

All ProLiant G6 servers support the PCIe 2.0 specification. PCIe 2.0 has a per-lane signaling rate of

5 Gb/s which is double the per-lane signaling rate of PCIe 1.0.

PCIe 2.0 is completely backward compatible with PCIe 1.0. A PCIe 2.0 device can be used in a

PCIe 1.0 slot and a PCIe 1.0 device can be used in a PCIe 2.0 slot. Table 2 shows the level of interoperability between PCIe cards and PCIe slots.

Table 2.

PCIe device interoperability

PCIe device type x4 card x8 card x4 Connector x4 Link x4 operation

Not allowed x8 Connector x4 Link x4 operation x4 operation x8 Connector x8 Link x4 operation x8 operation x16 Connector x8 Link x4 operation x8 operation x16 Connector x16 Link x4 operation x8 operation x16 card Not allowed Not allowed Not allowed x8 operation x16 operation

HP Smart Array and SAS/SATA technology

The newest serial PCIe 2.0-capable Smart Array controllers use Serial Attached SCSI (SAS) technology, a point-to-point architecture in which each device connects directly to a SAS port rather than sharing a common bus as with parallel SCSI devices. Point-to-point links increase data throughput and improve the ability to locate and fix disk failures. More importantly, SAS architecture solves the parallel SCSI problems of clock skew and signal degradation at higher signaling rates.

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The latest Smart Array controllers are compatible with SATA technology and include the following features to enhance performance and maintain data availability and reliability:

 SAS and SATA compatibility — SAS-2 compliance lets administrators deploy and manage both

SAS arrays and SATA arrays. Smart Array configuration utilities help administrators configure arrays correctly so that data remains available and reliable.



SAS wide port operations — Wide ports contain four single lane (1x) SAS connectors and the cabling bundles all four lanes together. SAS wide ports enhance performance by balancing SAS traffic across the links. In addition, wide ports provide redundancy by tolerating up to three physical link failures while maintaining the ability to communicate with the disk drives. The tolerance for link failures is possible because wide port connections are established from Phy

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to Phy, and multiple, simultaneous connections to different destinations are possible. The most common use of these wide links is to a JBOD or to an internal server expander connecting to large numbers of drives. No special configuration is required for this functionality.

 SAS expanders — Low-cost, high-speed switches called expanders can combine multiple single links to create wide ports and increase available bandwidth. SAS expander devices also offer higher system performance by expanding the number of hard drives that can be attached to an

HP Smart Array controller. SAS expanders are an aggregation point for large numbers of drives or servers providing a common connection. By cascading expanders, administrators can chain multiple storage boxes together. For more information on the HP SAS Expander Card, go to http://h18004.www1.hp.com/products/servers/proliantstorage/arraycontrollers/sasexpander/index.html.

2 For more information about SAS technology, refer to the HP technology brief titled “Serial Attached SCSI storage technology”

3 available at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01613420/c01613420.pdf .

The mechanism that contains a transceiver which electrically interfaces to a physical link. Phy is a common abbreviation for the physical layer of the OSI model.

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SAS-2

SAS-2 and PCIe 2.0 are among 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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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.

of

6 Gb/s is double the SAS-1 transfer rate. Operation at SAS-2 link speeds requires SAS-2 compliant

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 an 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

The Smart Array PCIe 2.0-based controllers are modular solutions with a common form factor, hardware, and firmware. Any of the ProLiant 100-series G6 servers can use PCIe 2.0-based controllers. All ProLiant 100-series G6 servers incorporate embedded SATA storage controllers, and the Smart Array B110i software RAID is available. The Smart Array 410 incorporates Zero Memory

RAID (ZMR) and is available as an entry level hardware-based RAID. Administrators can choose the cache size and can choose to include either the battery backed write cache (BBWC), or the Flashbacked write cache (FBWC). With these options, ZMR can be upgraded to 512 BBWC and up to 1

GB with the FBWC.

Battery backed write cache

The 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 extends battery life up to 48 hours before recharging becomes necessary.

NOTE:

The Smart Array P212 does not support 512 MB BBWC, and is only upgradeable to

256 MB BBWC

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 Batterybacked write-cache (BBWC) system. Since the FBWC writes the contents of memory to flash devices,

4 Serial Attached SCSI-2 (SAS-2) is an American National Standards Institute (ANSI) standard from the INCITS T10 Technical

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Committee on SCSI Storage Interfaces. SAS-2 is the successor to SAS-1.1 and SAS-1.

Non-volatile semiconductor memory that can be electronically erased and reprogrammed. No power is needed to maintain data stored in the chip

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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.

The FBWC DDR2 mini-DIMM cache module is specifically designed for the present generation of

PCIe2.0, SAS-based Smart Array controllers based on the PMC PM8011 SAS SRC 8x6G RAID on a chip (RoC). The primary FBWC components consist of the cache module, Super-caps with integrated charger, and RoC located on the system board.

At the time of this writing, the FBWC cache is supported on the Smart Array P410, P410i, P411,

P212, P812, and P712m.

For more information on the flash-backed write cache, see the “HP Smart Array Controller technology brief” at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00687518/c00687518.pdf.

Zero Memory RAID

Using Zero Memory RAID (ZMR), administrators can create a RAID 0-1 configuration without using any additional memory. Smart Array P410, P411, and P212 controllers include ZMR. The P212 controller does not include ZMR on the external connector. ZMR supports up to eight drives in Zero

Memory Mode, or seven drives and one tape drive. ZMR mode does not support Modular Smart

Array (MSA) products. ZMR does not include any caching. All systems can be upgraded to a BBWC or FBWC memory module that can significantly increase performance.

NOTE:

Smart Array Advanced Pack is not available on Zero Memory configurations.

S oftware RAID

HP has developed a software RAID solution based on the Smart Array firmware. The Smart Array

B110i SATA Software RAID supports the Array Configuration Utility (ACU), ACU-CLI (command line interface), Simple Network Management Protocol (SNMP) agents, and Web-Based Enterprise

Management (WBEM) providers.

Supported on the ProLiant DL160, DL170h, DL180, and ML150 G6 servers, the B110i features an

OS-specific driver from HP that uses the embedded ICH10R controller. It can utilize RAID 0, 1, and

1+0 and supports a maximum of two logical drives. The B110i supports up to four 1.5Gb or 3Gb

SATA drives. Because it is based on the Smart Array firmware, you can migrate drives to a hardwarebased Smart Array controller in a seamless procedure that maintains the user data and RAID configuration.

The Smart Array B110i also includes the following:



Support for up to six 3GB SATA drives on the DL170h G6



Support for solid state disks

 LED support

 SATA drive firmware flashing (offline)

Hot Plug technology

The HP Smart Array B110i SATA Raid Hot Plug Advance Pack provides hot-plug RAID support for the embedded SATA controller. The Hot Plug Advance Pack is available on the DL160, DL180, and

DL170h G6 servers as a license key on cold plug and hot plug models. The existing B110i Raid 0, 1,

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and 1+0 will continue to support selected G6 and G7 non-hot plug and cold plug models fee.

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with no

For more information about the B110i SATA Software RAID, download the B110i user guide at http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01706551/c01706551.pdf

Smart Array Advanced Pack

HP Smart Array Advanced Pack (SAAP) firmware provides advanced functionality within Smart Array controllers. This firmware further enhances performance, reliability, and data availability. The Smart

Array controller firmware stack supports SAAP. It can be enabled on the P212, P410, P410i, and

P411 controllers.

SAAP requires a license key for activation. After activation, administrators can employ several capabilities:



RAID 6 with Advanced Data Guarding (ADG) protects against failure of any two drives. It requires a minimum of four drives, but only two will be available for data. ADG can tolerate multiple simultaneous drive failures without downtime or data loss, and it is ideal for applications requiring large logical volumes because it can safely protect a single volume of up to 56 disk drives. RAID

ADG also offers lower implementation costs and greater usable capacity per U than RAID 1.

 RAID 60 allows administrators to split the RAID storage across multiple external boxes. It requires a minimum of eight drives, but only four will be available for data.

 Advanced Capacity Expansion (ACE) automates higher capacity migration using capacity transformation to remove logical drives by shrinking and then expanding them online. Standard drive migration and expansion remain unchanged.



Mirror Splitting and Recombining in Offline Mode breaks a RAID 1 configuration into two RAID 0 configurations. This is similar to a scaled down rollback functionality that requires two disk drives.



Drive Erase completely erases physical disks or logical volumes. This capability is useful when decommissioning, redeploying, or returning hard drives.



Video On Demand Performance Optimization decreases latency and improves video streaming.

More information about SAAP is available at www.hp.com/go/SAAP.

NOTE:

At a minimum, a 256 MB cache and battery kit is required to enable the SAAP license key. SAAP is not available on Zero Memory Configurations.

Solid state drives

HP has introduced the second generation of solid state drives (SSD) for ProLiant servers. These solid state drives are 3 Gb/s SATA interface in both 60GB and 120GB capacities. These drives, based on

NAND Single Level Cell flash technology, are implemented as SFF and LFF hot plug devices on the HP universal drive carrier for general use across the ProLiant portfolio. They deliver higher performance, lower latency, and low power solutions when compared with traditional rotating media.

You can use the HP second generation SSDs with the present generation Smart Array controllers

(based on the PM8011 SRC MIPS processor) on select ProLiant G6 and G7 servers. See the server

QuickSpecs to confirm that SSDs are supported.

6 Non-hot plug models cable hard drives directly from the motherboard. Cold plug models utilize a hard drive backplane but do not contain a hot plug HDD controller. These models can be upgraded to hot plug with the B110i software RAID advanced pack license, or with the introduction of a Smart Array hardware-based controller.

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