Contents ● 8
Understanding Adaptec Storage Manager
Features.............................................................................................................. 45
Overview............................................................................................................ 45
Physical Devices View................................................................................. 46
Logical Devices View ..................................................................................46
Changing How Drives are Displayed ............................................................... 46
Collapsed and Expanded Views ....................................................................... 47
Component Views............................................................................................. 48
Solving Problems
Troubleshooting Checklist ............................................................................... 50
Recovering from a Disk Drive Failure ............................................................. 50
Failed Disk Drive Protected by a Hot Spare.............................................. 50
Failed Disk Drive Not Protected by a Hot Spare....................................... 51
Failure in Multiple Arrays Simultaneously................................................ 51
Disk Drive Failure in a RAID 0 Array........................................................ 51
Multiple Failures in the Same Array .......................................................... 51
Introduction to SAS
Terminology Used in This Chapter ................................................................. 53
What is SAS?...................................................................................................... 53
How Do SAS Devices Communicate?.............................................................. 53
What’s a Phy? .................................................................................................... 54
What’s a SAS Port?............................................................................................ 54
What’s a SAS Address?...................................................................................... 55
What’s a SAS Connector? .................................................................................55
What do SAS Cables Look Like?....................................................................... 55
How are Disk Drives Identified in SAS? .......................................................... 55
What are the SAS Connection Options?.......................................................... 55
Direct-attach Connections ......................................................................... 56
Backplane Connections .............................................................................. 56
SAS Expander Connections........................................................................ 56
How is SAS Different from Parallel SCSI? ....................................................... 57
Understanding RAID
RAID Technology Overview............................................................................. 59
Understanding Drive Segments ................................................................. 59
Stripe-unit Size............................................................................................ 59
Selecting a RAID Level and Tuning Performance..................................... 59
RAID 0 (Non-RAID Arrays) ............................................................................ 60
RAID 1 Arrays ................................................................................................... 61
RAID 10 Arrays ................................................................................................. 61