Going the SAS Storage Way

Page 4 of 28:

SAS

Page 1: SAS Raises Storage Capabilities To Higher Power
Page 2: SCSI's Details And History
Page 3: From SATA
Page 4: SAS
Page 5: Expanders
Page 6: SAS Backplanes & Cables
Page 7: SAS As Part Of SAN Storage Solutions
Page 8: 2.5" SAS Hard Drives
Page 9: Fujitsu MAY2073RC
Page 10: 3.5" SAS Hard Drives
Page 11: Hitachi UltraStar 15K147 SAS (HUS151414VLS300)
Page 12: Maxtor Atlas 15KII
Page 13: Seagate Cheetah 15K.4B 147 GB (ST3146854SS)
Page 14: Host Adapters
Page 15: Adaptec SAS 48300
Page 16: RAID Adapters
Page 17: LSI Logic SAS3442X
Page 18: SAS Appliances And Enclosures
Page 19: Storage System
Page 20: Adaptec SANbloc S50 JBOD, Continued
Page 21: Test Setup
Page 22: Hard Drive Test Results
Page 23: 3.5" SAS Data Transfer Diagrams
Page 24: Data Transfer Performance
Page 25: Access Time
Page 26: I/O Performance
Page 27: SAS RAID Test Results (4 And 10 Drive Arrays)
Page 28: Conclusion

SAS

Here comes the neat thing: Serial Attached SCSI supports both SCSI and SATA, which enables SAS controllers to run either SAS or SATA devices (or both). However, SAS devices cannot be operated on SATA controllers because the Serial SCSI Protocol (SSP) is used. Like SATA, SAS follows the principle of point-to-point links to the drives (currently 300 MB/s), while there is the option to use SAS expanders for attaching more drives than SAS ports available. SAS hard drives are dual-ported, each featuring his unique SAS ID, which means that it is possible to use two physical data connections to provide redundant data paths to two different hops/hosts. Thanks to STP (SATA Tunneling Protocol), SAS controllers will still be able to talk to SATA drives that are attached to an expander.