Going the SAS Storage Way
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Page 1:SAS Raises Storage Capabilities To Higher Power
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Page 2:SCSI's Details And History
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Page 3:From SATA
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Page 4:SAS
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Page 5:Expanders
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Page 6:SAS Backplanes & Cables
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Page 7:SAS As Part Of SAN Storage Solutions
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Page 8:2.5" SAS Hard Drives
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Page 9:Fujitsu MAY2073RC
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Page 10:3.5" SAS Hard Drives
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Page 11:Hitachi UltraStar 15K147 SAS (HUS151414VLS300)
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Page 12:Maxtor Atlas 15KII
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Page 13:Seagate Cheetah 15K.4B 147 GB (ST3146854SS)
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Page 14:Host Adapters
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Page 15:Adaptec SAS 48300
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Page 16:RAID Adapters
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Page 17:LSI Logic SAS3442X
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Page 18:SAS Appliances And Enclosures
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Page 19:Storage System
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Page 20:Adaptec SANbloc S50 JBOD, Continued
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Page 21:Test Setup
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Page 22:Hard Drive Test Results
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Page 23:3.5" SAS Data Transfer Diagrams
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Page 24:Data Transfer Performance
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Page 25:Access Time
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Page 26:I/O Performance
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Page 27:SAS RAID Test Results (4 And 10 Drive Arrays)
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Page 28:Conclusion
Host Adapters
Unlike SATA controllers, SAS components will only be found on server class motherboards or as separate add-in cards for PCI-X or PCI Express. If you take another step forward and look at RAID controllers (Redundant Array of Inexpensive Drives), these are mostly sold as add-in cards due to their complexity. RAID cards do not only include the actual controller, but they have a hardware accelerator for parity calculation (called the XOR engine) as well as some cache memory. A limited amount is either soldered onto the controller card (usually up to 128 MB), or some cards allow for installing a DIMM or SO-DIMM instead.
You should identify your requirements first when selecting a host adapter or RAID controller, as there is an increasing range of products. Simple multi-port host adapters will be relatively cheap, while powerful RAID cards usually are a considerable investment. Think of where to place your storage devices as well: Using storage boxes requires at least one external connector. Rack mount server scenarios sometimes require low profile add-in cards.
If you think RAID, determine whether or not you need hardware acceleration. Some RAID cards burden the system processor(s) with XOR calculation for RAID 5 or 6; others have an XOR offload engine. Accelerated RAID is required for environments in which a server is not dedicated to storage only, such as databases and Web services.
All the host adapter cards that we present on the following pages support 300 MB/s speed per SAS port and are as flexible as described above when it comes to storage infrastructures. External ports are pretty much standard already, and both SAS and SATA hard drives are supported. All three cards use the PCI-X interface, but PCI Express versions are already in development.
Although all cards in this article are eight port models, this does not limit the maximum number of disk drives. Using a SAS expander (externally), you can attach all types of storage appliances to any of these adapters. As long as the quad link connection is fast enough for your applications, up to 122 drives are supported by the SAS protocol. Due to the performance impact of parity added RAID 5 or RAID 6, typical RAID setups will not be able to saturate the bandwidth of these quad links even when multiple drives are being used.
- SAS Raises Storage Capabilities To Higher Power
- SCSI's Details And History
- From SATA
- SAS
- Expanders
- SAS Backplanes & Cables
- SAS As Part Of SAN Storage Solutions
- 2.5" SAS Hard Drives
- Fujitsu MAY2073RC
- 3.5" SAS Hard Drives
- Hitachi UltraStar 15K147 SAS (HUS151414VLS300)
- Maxtor Atlas 15KII
- Seagate Cheetah 15K.4B 147 GB (ST3146854SS)
- Host Adapters
- Adaptec SAS 48300
- RAID Adapters
- LSI Logic SAS3442X
- SAS Appliances And Enclosures
- Storage System
- Adaptec SANbloc S50 JBOD, Continued
- Test Setup
- Hard Drive Test Results
- 3.5" SAS Data Transfer Diagrams
- Data Transfer Performance
- Access Time
- I/O Performance
- SAS RAID Test Results (4 And 10 Drive Arrays)
- Conclusion