Embodiments of this invention relate to computing devices, and in particular to an improvement in connecting multiple hard drives to a computer. Specifically embodiments of the invention deal with SATA and SAS hard drive connections.
Traditionally, each hard drive had to be connected to an individual SATA or SAS interface port. Commonly computers would have less than 4 hard drives, and thus computers are typically built with 4 to 6 ports. Ports may be physically part of the motherboard, or an add-on SATAISAS interface board. However, there is presently an explosion in the amount of data storage, driven by dropping prices on hard drives and storage intensive applications like images and video. This requires more hard drive ports, which increases system cost and consumes computing resources.
Thus storage servers and pods with large numbers of hard drives are becoming increasing necessary. The need for increased storage was addressed some years ago with the introduction of a backplanes. The primary function of a backplane is to multiplex multiple hard drives, in a manner such that they can be connected to one data port on the computer. For example,
Another major function of backplanes is that they physically mount/constrain connectors, such that they constrain the connector end of the hard drive and can form part of a hard drive physical mount in a computer. (Traditionally. hard drives were physically mounted. and the cabling and connectors had nothing to do with restraining the drive.)
Most hard drives were cabled via ‘standard SATA cables’. One cable connected the data connector on the hard drive. to its corresponding interface port on the computer. The next innovation was the 8087 connector which combined the data connections for four SAS/SATA ports (SFF8482 connectors). These connectors can be used to fan out from a single 8087 4 port connection to four hard drives via 4 SFF8482 connectors (the connector on the other end can be 8087's, or ‘standard SATA/SAS data connectors). These cabling advances only reduce the number of connectors, but NOT the number of ports.
Host bus adaptors (HBA's) are interface cards that provide multiple SATA/SAS ports and connect them to the computer's internal busses. Recent advances have seen the introduction of faster and larger (in terms of number of ports) HBA's.
When adding multiple hard drives to a server, the conventional method is to use a backplane 10 as pictured in
Although such backplanes are advantageous in reducing the number of ports required through multiplexing, their major drawback is that the bandwidth of the connection is shared through across multiple drives on a single port.
Another drawback of traditional backplanes is that they increase parts count and system complexity. This increases failure modes and reduces reliability, relative to direct cabling from drive to port.
Another obstacle is that backplanes are constantly being upgraded or go End of Life. This requires a change in design as the product matures, creating multiple versions of the same product with different hardware and software payloads.
Embodiments of the present invention provide the advantages of a backplane in terms of its ability to physically arrange and secure the connector ends of multiple hard drives, with the speed, simplicity, and reliability of direct wired connections.
Embodiments of the present invention may provide some of the following advantages:
Eliminate drivers and special software needed to operate traditional back planes, since a driver package that will allow the back plane hardware to communicate with all the hard drives on the back plane must be provided.
Fewer points of failure by eliminating the electronics and circuit boards on the backplane itself, and increased simplification since the hard drives are connected to ports by a wire.
Longer life than traditional backplanes since the circuit boards and chips are no longer part of the backplane.
Discrete connections for the HBA to fully control each drive without port multiplication or manipulation from electronic back plane. In embodiments of the present invention, the HBA communicates directly to the hard drive, rather than having the HBA speak to a group of hard drives through a port multiplier requiring a software driver to control drive addressing.
Discrete wiring allows easy monitoring of each drive from the HBA card. The hard drives are connected electronically to the RBA cards by direct wiring. They are physically mounted by a metal grid and cap to restrain the drives.
No interference from the backplane to utilize Hard Drive RAID Control from the HBA card without dealing with drivers and software to utilize electronic back planes. In embodiments of the invention, hardware RAID is implemented on the HBA hard drive controller board. RAID functionality is offloaded to dedicated hardware so it is typically faster, and it simplifies the OS (RAID functionality does not have to be built in, one configures RAID through a software utility and the OS sees a group of RAID drives as a single hardware device. The RAID HBA controller does not recognize or understand Port Multiplier boards. The Software driver that is added to deal with that layer of complexity is on the motherboard/operating system side of things, so it cannot intervene and do the required translation (Hardware RAID is an arrangement between the HBA and hard drives only). So it cannot work with Port Multiplier backplane boards.
Embodiments of the invention will now be described in conjunction with the accompanying drawings, wherein:
a and 7b illustrate the present way to connect drives with standard SFF8087 to 4 SFF8482 cables;
a illustrates another embodiment of a backplane in accordance with the teachings of this invention;
b illustrates a pre-wired cable and backplane system using the backplane of
a in accordance with the teachings of this invention;
a illustrates a block diagram of the electrical communication between components of a conventional system; and
b illustrates a block diagram of the electrical communication between components of an embodiment of the present invention in use.
This invention will now be described in detail with respect to certain specific representative embodiments thereof, the materials, apparatus and process steps being understood as examples that are intended to be illustrative only. In particular, the invention is not intended to be limited to the methods, materials, conditions, process parameters, apparatus and the like specifically recited herein.
In the past, the drives would be mounted in the unit and the cables 40 like the one seen in
Referring to the fasteners 55 of
In this embodiment, the fastener 55 has through holes 58 to allow for mounting screws or rivet 91. With such an embodiment, the mechanical backplane 60 of
As long as the hard drives maintain the SATA/SAS standard for connection, these cables in accordance with the teachings of this invention will have a long term ability to connect to any HBA card, such as HBA card 20 seen in
Off-the-shelf HBA cards now provide large numbers of very high speed ports, while minimizing the load on the host computer's resources. This allows direct wired connection of many hard drives. Embodiments of the present invention arranges the direct wired connection such that instead of having a rat's nest of wires as well as physical mounts for hard drives, there is one component that resembles a backplane in look and function (providing physically arranged and constrained connectors that provide mounting constraint for the connector end of the hard drive) and organized wiring with reduced number of connections. The new ability to affix the SFF8482 connectors to a surface gives a huge advantage over standard SFF8482 connectors. Using embodiments of the present invention, the SFF8482 connectors can be attached to a surface and then systematically arrange the wiring in such a way it does not impede hard drive installation and allow the wiring to be systematically harnessed and channeled away. This makes the installation of drives using this method trouble free and very easy to identify wiring locations without tracing wire looms and harness connections,
Engineering changes in the RBA cards have allowed them to Direct Wire more drives. These engineering changes and lower costs of these HBA cards now allow options to direct wire quantities of drives that in the past could only be done with fewer connections to HBA cards and then port multiplying the HBA outputs on back planes to achieve a higher drive count.
Discrete wiring allows easy monitoring of each drive from the HBA card. Discrete connections for the HBA permit control of each drive without port multiplication or manipulation from electronic back plane.
Previously, backplanes required special software to allow them to be used for RAIDS, their drivers would be needed to communicate with all the drives on the back plane. Software and Hardware RAIDS cannot communicate with the back planes to either identify the drives or allow them to pass data to the drives in an effective manner thus either. Embodiments of the present invention require no special communication drivers to allow setting up RAIDS. Embodiments of the present invention allows HBA ports to connect directly to hard drives, so that no driver is required to direct data through port multipliers. Software RAID can move directly to drives without going through another driver (less complicated). Hardware raid becomes possible. In this way, there is no interference from the back plane to utilize Hard Drive RAID Control from the HBA card without dealing with drivers and software to utilize electronic back planes. The drive multiplexing that occurs on the backplane muddles the hard drive controller's view of each drive, so RAID and drive monitoring functionality is confused. In embodiments of the present inventions, each drive is directly connected to the motherboard, therefore there is no need for software to allow the motherboard to recognize all the drives on a back plane. As for the bandwidth issues when each connection to the hard drives is at full transfer speed per drive and does not share one connection at full transfer speed with multiple drives when using back planes.
Traditional backplanes require driver software packages to allow them to connect to the drives; usually without driver software packages they will only allow the use of the partial drives attached to the back plane. Embodiments of this present invention allow each drive to be connected directly to the motherboard without the need for back planes or drivers. In this way, embodiments of the present invention eliminate drivers and special software to operate traditional backplanes.
Another issue with traditional backplane and HBA systems is they need to have the same manufacturer of communication hardware chip sets making the choice of back planes and NBA card limited to the same families of chipset. In contrast, embodiments of the present invention eliminate the need for this requirement of chipset compatibility. A chipset is a set of electronic components in an integrated circuit that manages the data flow that allows communication from HBA to backplane. Chipsets are found on the HBA and another set are found on the back plane. These chip sets will loosely follow SATA/SAS protocols but many manufacturers provide some proprietary communication commands and protocols. These commands will usually not allow communication between HBA cards and back planes of different ChipSet manufacturers.
Embodiments of the invention can also offer the advantage of fewer points of failure and elimination of the electronics on the backplane. In a conventional system, backplanes 10 (such as those seen in
In one practical embodiment, the Applicants utilize a Syba PCI Express SATA II 4-Port RAID Controller Card SY-PEX40008 HBA card with 4 ports and we attach 3 AC-SAN-5PMBP 5 Bay Port Multiplier Backplane, which permits expansion to 3 ports on the SYBA HBA card to 15 Drives. The process of mounting these cables to the mechanical back plane provides the means to easily attach and remove hard drives to a storage system without the mess of complicated cabling of
Numerous modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Number | Date | Country | |
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61907057 | Nov 2013 | US |