readme.dac960

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

asynchronous rebuild operation:

DAC960#0: Rebuild of Physical Drive 1:1 Initiated
DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01
DAC960#0: Physical Drive 1:1 is now WRITE-ONLY
DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 1% completed

and /proc/rd/c0/current_status is updated:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Write-Only, 2201600 blocks
    1:2 - Disk: Online, 2201600 blocks
    1:3 - Disk: Online, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru
  Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 6% completed

As the rebuild progresses, the current status in /proc/rd/c0/current_status is
updated every 10 seconds:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Write-Only, 2201600 blocks
    1:2 - Disk: Online, 2201600 blocks
    1:3 - Disk: Online, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru
  Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 15% completed

and every minute a progress message is logged to the console by the driver:

DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 32% completed
DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 63% completed
DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 94% completed
DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 94% completed

Finally, the rebuild completes successfully.  The driver logs the status of the 
logical and physical drives and the rebuild completion:

DAC960#0: Rebuild Completed Successfully
DAC960#0: Physical Drive 1:1 is now ONLINE
DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE
DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE

/proc/rd/c0/current_status is updated:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Online, 2201600 blocks
    1:3 - Disk: Online, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Online, 5498880 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Online, 3305472 blocks, Write Thru
  Rebuild Completed Successfully

and /proc/rd/status indicates that everything is healthy once again:

gwynedd:/u/lnz# cat /proc/rd/status
OK


		EXAMPLE II - DRIVE FAILURE WITH A STANDBY DRIVE

The following annotated logs demonstrate the controller configuration and and
online status monitoring capabilities of the Linux DAC960 Driver.  The test
configuration comprises 6 1GB Quantum Atlas I disk drives on two channels of a
DAC960PJ controller.  The physical drives are configured into a single drive
group with a standby drive, and the drive group has been configured into two
logical drives, one RAID-5 and one RAID-6.  Note that these logs are from an
earlier version of the driver and the messages have changed somewhat with newer
releases, but the functionality remains similar.  First, here is the current
status of the RAID configuration:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 *****
Copyright 1998-1999 by Leonard N. Zubkoff <[e-mail]>
Configuring Mylex DAC960PJ PCI RAID Controller
  Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB
  PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned
  PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9
  Controller Queue Depth: 128, Maximum Blocks per Command: 128
  Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33
  Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Online, 2201600 blocks
    1:3 - Disk: Standby, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru
  No Rebuild or Consistency Check in Progress

gwynedd:/u/lnz# cat /proc/rd/status
OK

The above messages indicate that everything is healthy, and /proc/rd/status
returns "OK" indicating that there are no problems with any DAC960 controller
in the system.  For demonstration purposes, while I/O is active Physical Drive
1:2 is now disconnected, simulating a drive failure.  The failure is noted by
the driver within 10 seconds of the controller's having detected it, and the
driver logs the following console status messages:

DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02
DAC960#0: Physical Drive 1:3 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02
DAC960#0: Physical Drive 1:2 killed because of timeout on SCSI command
DAC960#0: Physical Drive 1:2 is now DEAD
DAC960#0: Physical Drive 1:2 killed because it was removed
DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now CRITICAL
DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now CRITICAL

Since a standby drive is configured, the controller automatically begins
rebuilding onto the standby drive:

DAC960#0: Physical Drive 1:3 is now WRITE-ONLY
DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed

Concurrently with the above, the driver status available from /proc/rd also
reflects the drive failure and automatic rebuild.  The status message in
/proc/rd/status has changed from "OK" to "ALERT":

gwynedd:/u/lnz# cat /proc/rd/status
ALERT

and /proc/rd/c0/current_status has been updated:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Dead, 2201600 blocks
    1:3 - Disk: Write-Only, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru
  Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed

As the rebuild progresses, the current status in /proc/rd/c0/current_status is
updated every 10 seconds:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Dead, 2201600 blocks
    1:3 - Disk: Write-Only, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru
  Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed

and every minute a progress message is logged on the console by the driver:

DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed
DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 76% completed
DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 66% completed
DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 84% completed

Finally, the rebuild completes successfully.  The driver logs the status of the 
logical and physical drives and the rebuild completion:

DAC960#0: Rebuild Completed Successfully
DAC960#0: Physical Drive 1:3 is now ONLINE
DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE
DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE

/proc/rd/c0/current_status is updated:

***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 *****
Copyright 1998-1999 by Leonard N. Zubkoff <[e-mail]>
Configuring Mylex DAC960PJ PCI RAID Controller
  Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB
  PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned
  PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9
  Controller Queue Depth: 128, Maximum Blocks per Command: 128
  Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33
  Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Dead, 2201600 blocks
    1:3 - Disk: Online, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru
  Rebuild Completed Successfully

and /proc/rd/status indicates that everything is healthy once again:

gwynedd:/u/lnz# cat /proc/rd/status
OK

Note that the absence of a viable standby drive does not create an "ALERT"
status.  Once dead Physical Drive 1:2 has been replaced, the controller must be
told that this has occurred and that the newly replaced drive should become the
new standby drive:

gwynedd:/u/lnz# echo "make-standby 1:2" > /proc/rd/c0/user_command
gwynedd:/u/lnz# cat /proc/rd/c0/user_command
Make Standby of Physical Drive 1:2 Succeeded

The echo command instructs the controller to make Physical Drive 1:2 into a
standby drive, and the status message that results from the operation is then
available for reading from /proc/rd/c0/user_command, as well as being logged to
the console by the driver.  Within 60 seconds of this command the driver logs:

DAC960#0: Physical Drive 1:2 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01
DAC960#0: Physical Drive 1:2 is now STANDBY
DAC960#0: Make Standby of Physical Drive 1:2 Succeeded

and /proc/rd/c0/current_status is updated:

gwynedd:/u/lnz# cat /proc/rd/c0/current_status
  ...
  Physical Devices:
    0:1 - Disk: Online, 2201600 blocks
    0:2 - Disk: Online, 2201600 blocks
    0:3 - Disk: Online, 2201600 blocks
    1:1 - Disk: Online, 2201600 blocks
    1:2 - Disk: Standby, 2201600 blocks
    1:3 - Disk: Online, 2201600 blocks
  Logical Drives:
    /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru
    /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru
  Rebuild Completed Successfully