SCSI Command Utility August 10th, 1995

What's New as of August 10th, 1995

Changes For This Release

The following changes have been made to scu for this release:

Added ability to change density code, block length, capacity (number of blocks), and device specific parameters.
The "seek lba n" is now equivalent to "set position lba n" command.
start/stop/eject commands now take optional "immediate" keyword.
Added ability to set individual page fields. A "show layout" command was also added to display the mode page field names.
If undocumented BypassFlag is enabled, allow changing page fields marked as unchangeable (some firmware is incorrect).
Finished rewrite of "show defects" functions, which also involved changing display format to be more user friendly. Also relaxed parsing restrictions on defect list/format args.
Added hooks to allow addition of vendor unique mode pages, and added two RWZ52 pages (0x20 & 0x21 which are very useful).
[ NOTE: the long range plan is to support vendor unique pages from a data file, instead of modifying scu program. ]
Fixed problem with mode page related commands failing silently.
[ i.e., "verify media recovery off" would do nothing if the device did _not_ support a verify error recovery page. ]
Add dynamic bad block replacment (auto-reassign) option and implement for media analysis commands (read/write/scan/verify).
Add detection of screen width to control field dump size.
[ struct winsize win; ioctl(fd, TIOCGWINSZ, &win), win.ws_col ]
[ Also add signal handler to detect window change to recheck. ]
Merged new dump_buffer code from dt into scu, which gets used during data compare errors (more informative).
Allow user to disable auto-sense via setting CAM_DIS_AUTOSENSE. Basically, you can disable auto-sense via "set cam flags 0x20".
Add "zero sense" command to force request sense on "show sense".
Added "set sense { brief | full }" to control sense reporting.

That's it for now. See scu help file for additional information. As always, send mail directly to me if you encounter any problems and/or have questions.

Within Compaq, the updated scu kits are located @ URL:

http://www.zk3.dec.com/~rmiller/scu.html

Send mail to admin of this page: Robin.Miller@compaq.com

To Robin's home page.

Last modified: December 29th, 1999

Examples:

Examples of Mode Page extensions:

imfaster% scu
scu> set nexus pid 1 tid 0 lun 0
Device: RWZ52, Bus: 1, Target: 0, Lun: 0, Type: Optical
scu> show pages supported
Mode Pages Supported by Device [1/0/0] (RWZ52):

Read-Write Error Recovery Page (0x01), Page Length 10 (0x0a), Savable Yes
     Disconnect-Reconnect Page (0x02), Page Length 14 (0x0e), Savable Yes
      Rigid Disk Geometry Page (0x04), Page Length 22 (0x16), Savable No
           Optical Memory Page (0x06), Page Length  2 (0x02), Savable Yes
    Verify Error Recovery Page (0x07), Page Length 10 (0x0a), Savable Yes
            Cache Control Page (0x08), Page Length 10 (0x0a), Savable Yes
   Medium Types Supported Page (0x0b), Page Length  6 (0x06), Savable Yes
          Vendor Specific Page (0x20), Page Length 12 (0x0c), Savable Yes
          Vendor Specific Page (0x21), Page Length 10 (0x0a), Savable Yes

scu> show page vendor 0x21

Vendor Specific Parameters (Page 0x21 - Current Values):

Mode Parameter Header:

                  Mode Data Length: 23
                       Medium Type: 0x3 (Reversible or Erasable medium)
         Device Specific Parameter: 0x10 (Supports cache memory)
           Block Descriptor Length: 8

Mode Parameter Block Descriptor:

                      Density Code: 0xa
          Number of Logical Blocks: 1163337
              Logical Block Length: 512

Page Header / Data:
                         Page Code: 0x21
                Parameters Savable: Yes
                       Page Length: 10
 Direct Access Inquiry Resp (DAIR): No
 Disable Tgt Initiated Sync (DTIS): Yes
         Disable Auto Spinup (DAS): No
       Reset Configuration (Reset): Off (hard reset)
   Correction Manager Log (CM Log): Disabled
        Drive Manager Log (DM Log): Disabled
 Digital Signal Proc Log (DSP Log): Disabled
 Extended Recovery Reporting (ERR): No
 Timestamps for Q Log and Task Log: Disabled
Task Log Change Logging (Task Log): Disabled
    Priority Queue Logging (Q Log): Disabled
  Disable Log Thresold Warn (DLTW): Yes
        Force Verify on ALL Writes: Yes
       Reserved (byte 3, bits 5:7): 0x2
            Maximum Buffer Latency: 1000ms
                 Drive Retry Count: 2
        Autochanger Eject Distance: 150 (1.5 millimeters)
      SCSI Phase Retry Error Count: 5

scu>


Examples of "show layout" command and setting individual page fields:

scu> set nexus pid 1 tid 0 lun 0
Device: RWZ52, Bus: 1, Target: 0, Lun: 0, Type: Optical
scu> show layout cache

                     Cache Control Page Layout (Page 0x8)

    Field Description & Offset/Bit Information        Set Name
    ------------------------------------------        --------
          Read Cache Disable (RCD) (byte 2, bit 0) -> rcd
        Multiplication Factor (MF) (byte 2, bit 1) -> mf
          Write Cache Enable (WCE) (byte 2, bit 2) -> wce
                       Reserved (byte 2, bits 3:7) -> 
       Write Retention Priority (byte 3, bits 0:3) -> write_retention_pri
 Demand Read Retention Priority (byte 3, bits 4:7) -> demand_read_ret_pri
      Disable Prefetch Transfer Length (bytes 4-5) -> prefetch_xfer_len
                      Minimum Prefetch (bytes 6-7) -> minimum_prefetch
                      Maximum Prefetch (bytes 8-9) -> maximum_prefetch
            Maximum Prefetch Ceiling (bytes 10-11) -> max_prefetch_ceiling

scu> show page cache

Cache Control Parameters (Page 0x8 - Current Values):

Mode Parameter Header:

                  Mode Data Length: 23
                       Medium Type: 0x3 (Reversible or Erasable medium)
         Device Specific Parameter: 0x10 (Supports cache memory)
           Block Descriptor Length: 8

Mode Parameter Block Descriptor:

                      Density Code: 0xa
          Number of Logical Blocks: 1163337
              Logical Block Length: 512

Page Header / Data:
                         Page Code: 0x8
                Parameters Savable: Yes
                       Page Length: 10
          Read Cache Disable (RCD): No
        Multiplication Factor (MF): Off
          Write Cache Enable (WCE): No
          Write Retention Priority: 0 (Not distiguished)
    Demand Read Retention Priority: 0 (Not distiguished)
  Disable Prefetch Transfer Length: 65535 blocks
                  Minimum Prefetch: 4 blocks
                  Maximum Prefetch: 8 blocks
          Maximum Prefetch Ceiling: 0 blocks

scu> set default savable off
scu> set page cache rcd yes wce on
Setting Cache Control Parameters (Page 0x8 - Current Values):
scu> show page cache

Cache Control Parameters (Page 0x8 - Current Values):

Mode Parameter Header:

                  Mode Data Length: 23
                       Medium Type: 0x3 (Reversible or Erasable medium)
         Device Specific Parameter: 0x10 (Supports cache memory)
           Block Descriptor Length: 8

Mode Parameter Block Descriptor:

                      Density Code: 0xa
          Number of Logical Blocks: 1163337
              Logical Block Length: 512

Page Header / Data:
                         Page Code: 0x8
                Parameters Savable: Yes
                       Page Length: 10
          Read Cache Disable (RCD): Yes
        Multiplication Factor (MF): Off
          Write Cache Enable (WCE): Yes
          Write Retention Priority: 0 (Not distiguished)
    Demand Read Retention Priority: 0 (Not distiguished)
  Disable Prefetch Transfer Length: 65535 blocks
                  Minimum Prefetch: 4 blocks
                  Maximum Prefetch: 8 blocks
          Maximum Prefetch Ceiling: 0 blocks

scu>

Example of switch RWZ52 Optical to Direct-Access mode:

scu> set nexus pid 1 tid 0 lun 0
Device: RWZ52, Bus: 1, Target: 0, Lun: 0, Type: Optical
scu> show inquiry
Inquiry Information:

            Peripheral Device Type: 0x7 (Optical)
              Peripheral Qualifier: 0 (Peripheral Device Connected)
              Device Type Modifier: 0
                   Removable Media: Yes
                      ANSI Version: 2 (Complies to ANSI X3.131-1994, SCSI-2)
                      ECMA Version: 0
                       ISO Version: 0
              Response Data Format: 2 (SCSI-2)
             Terminate I/O Process: 0
         Asynchronous Notification: 0
                 Additional Length: 51
                Soft Reset Support: No
           Command Queuing Support: No
           Target Transfer Disable: No
            Linked Command Support: No
        Synchronous Data Transfers: Yes
      Support for 16 Bit Transfers: No
      Support for 32 Bit Transfers: No
       Relative Addressing Support: No
             Vendor Identification: DEC     
            Product Identification: RWZ52     (C)DEC
           Firmware Revision Level: 3404
              Vendor Specific Data: 33 33 35 31 00 0a 02 00 00 00 00 00 00 00 "3351          "
                                    00 00 00 00 00 00                         "      "
scu> show layout vendor 0x21

                    Vendor Specific Page Layout (Page 0x21)

    Field Description & Offset/Bit Information        Set Name
    ------------------------------------------        --------
 Direct Access Inquiry Resp (DAIR) (byte 2, bit 0) -> dair
 Disable Tgt Initiated Sync (DTIS) (byte 2, bit 1) -> dtis
         Disable Auto Spinup (DAS) (byte 2, bit 2) -> das
       Reset Configuration (Reset) (byte 2, bit 3) -> reset
   Correction Manager Log (CM Log) (byte 2, bit 4) -> cmlog
        Drive Manager Log (DM Log) (byte 2, bit 5) -> dmlog
 Digital Signal Proc Log (DSP Log) (byte 2, bit 6) -> dsplog
 Extended Recovery Reporting (ERR) (byte 2, bit 7) -> err
 Timestamps for Q Log and Task Log (byte 3, bit 0) -> timestamp
Task Log Change Logging (Task Log) (byte 3, bit 1) -> tasklog
    Priority Queue Logging (Q Log) (byte 3, bit 2) -> qlog
  Disable Log Thresold Warn (DLTW) (byte 3, bit 3) -> dltw
        Force Verify on ALL Writes (byte 3, bit 4) -> force_verify
                       Reserved (byte 3, bits 5:7) -> 
                Maximum Buffer Latency (bytes 4-7) -> buffer_latency
                        Drive Retry Count (byte 8) -> drive_retrys
               Autochanger Eject Distance (byte 9) -> eject_distance
            SCSI Phase Retry Error Count (byte 10) -> phase_retrys
                                Reserved (byte 11) -> 

scu> 
scu> set page vendor 0x21 dair on
Setting & Saving Vendor Specific Parameters (Page 0x21 - Current Values):
scu> show inquiry
Inquiry Information:

            Peripheral Device Type: 0 (Direct Access)
              Peripheral Qualifier: 0 (Peripheral Device Connected)
              Device Type Modifier: 0
                   Removable Media: Yes
                      ANSI Version: 2 (Complies to ANSI X3.131-1994, SCSI-2)
                      ECMA Version: 0
                       ISO Version: 0
              Response Data Format: 2 (SCSI-2)
             Terminate I/O Process: 0
         Asynchronous Notification: 0
                 Additional Length: 51
                Soft Reset Support: No
           Command Queuing Support: No
           Target Transfer Disable: No
            Linked Command Support: No
        Synchronous Data Transfers: Yes
      Support for 16 Bit Transfers: No
      Support for 32 Bit Transfers: No
       Relative Addressing Support: No
             Vendor Identification: DEC     
            Product Identification: RWZ52     (C)DEC
           Firmware Revision Level: 3404
              Vendor Specific Data: 33 33 35 31 00 0a 02 00 00 00 00 00 00 00 "3351          "
                                    00 00 00 00 00 00                         "      "
scu> 

Examples of displaying all page control fields (tty width was 100 columns):

scu> show pages pcf all
Mode Page Parameters for Device [1/0/0] (RWZ52):

Current Pages:

    Mode Header & Block Descriptor: 00 80 03 10 00 00 00 08 0a 11 c0 49 00 00 02 00 
    Read-Write Error Recovery Page: 81 0a a0 05 00 00 00 00 02 00 00 00 
         Disconnect-Reconnect Page: 82 0e 80 00 00 00 00 00 00 00 00 20 00 00 00 00 
          Rigid Disk Geometry Page: 04 16 00 92 96 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                    09 60 00 00 
               Optical Memory Page: 86 02 00 00 
        Verify Error Recovery Page: 87 0a 00 05 00 00 00 00 00 00 00 00 
                Cache Control Page: 88 0a 05 00 ff ff 00 04 00 08 00 00 
       Medium Types Supported Page: 8b 06 00 00 02 03 00 00 
              Vendor Specific Page: a0 0c 00 00 01 00 00 00 00 00 00 1f 00 00 
              Vendor Specific Page: a1 0a 02 58 00 00 03 e8 02 96 05 00 

Changeable Pages:

    Mode Header & Block Descriptor: 00 80 00 00 00 00 00 08 00 00 00 00 00 00 00 00 
    Read-Write Error Recovery Page: 81 0a a7 ff 00 00 00 00 ff 00 00 00 
         Disconnect-Reconnect Page: 82 0e ff 00 00 00 00 00 00 00 ff ff 00 00 00 00 
          Rigid Disk Geometry Page: 04 16 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                    00 00 00 00 
               Optical Memory Page: 86 02 00 00 
        Verify Error Recovery Page: 87 0a 05 ff 00 00 00 00 00 00 00 00 
                Cache Control Page: 88 0a 05 00 ff ff ff ff ff ff 00 00 
       Medium Types Supported Page: 8b 06 00 00 00 00 00 00 
              Vendor Specific Page: a0 0c 00 ff ff ff ff ff ff ff ff 00 00 00 
              Vendor Specific Page: a1 0a ff ff ff ff ff ff ff ff ff 00 

Default Pages:

    Mode Header & Block Descriptor: 00 80 03 10 00 00 00 08 0a 11 c0 49 00 00 02 00 
    Read-Write Error Recovery Page: 81 0a 80 08 00 00 00 00 02 00 00 00 
         Disconnect-Reconnect Page: 82 0e 80 00 00 00 00 00 00 00 00 20 00 00 00 00 
          Rigid Disk Geometry Page: 04 16 00 92 96 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                    09 60 00 00 
               Optical Memory Page: 86 02 00 00 
        Verify Error Recovery Page: 87 0a 00 05 00 00 00 00 00 00 00 00 
                Cache Control Page: 88 0a 04 00 ff ff 00 08 00 08 00 00 
       Medium Types Supported Page: 8b 06 00 00 02 03 00 00 
              Vendor Specific Page: a0 0c 00 00 00 00 00 00 00 00 00 1f 00 00 
              Vendor Specific Page: a1 0a 02 08 00 00 03 e8 02 96 05 00 

Saved Pages:

    Mode Header & Block Descriptor: 00 80 03 10 00 00 00 08 0a 11 c0 49 00 00 02 00 
    Read-Write Error Recovery Page: 81 0a a0 05 00 00 00 00 02 00 00 00 
         Disconnect-Reconnect Page: 82 0e 80 00 00 00 00 00 00 00 00 20 00 00 00 00 
          Rigid Disk Geometry Page: 04 16 00 92 96 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                    09 60 00 00 
               Optical Memory Page: 86 02 00 00 
        Verify Error Recovery Page: 87 0a 00 05 00 00 00 00 00 00 00 00 
                Cache Control Page: 88 0a 00 00 ff ff 00 04 00 08 00 00 
       Medium Types Supported Page: 8b 06 00 00 02 03 00 00 
              Vendor Specific Page: a0 0c 00 00 00 00 00 00 00 00 00 1f 00 00 
              Vendor Specific Page: a1 0a 02 58 00 00 03 e8 02 96 05 00 
scu> 
scu> show page cache pcf all
Mode Page Parameters for Device [1/0/0] (RWZ52):

Cache Control Page (0x08):

      Headers: 17 03 10 08 0a 11 c0 49 00 00 02 00 
      Current: 88 0a 05 00 ff ff 00 04 00 08 00 00 
   Changeable: 88 0a 05 00 ff ff ff ff ff ff 00 00 
      Default: 88 0a 04 00 ff ff 00 08 00 08 00 00 
        Saved: 88 0a 00 00 ff ff 00 04 00 08 00 00 
scu> 

Example of Dynamic Bad Block Replacement enhancement & "show defects" display:

scu> show capacity
Disk Capacity Information:

                  Maximum Capacity: 409792 (200.094 megabytes)
                      Block Length: 512
scu> 
scu> verify media starting 409700 dbbr on
Verifying 92 blocks (409700 - 409791) on /dev/rrz0c (RZ24), please be patient...
Verifying blocks [ 409700 through 409791 ]...
scu: Verify error at logical block number 409725 (0x6407d).
scu: Sense Key = 0x3 = MEDIUM ERROR - Nonrecoverable medium error,
     Sense Code/Qualifier = (0x11, 0) = Unrecovered read error
Attempting to reassign logical block 409725 on /dev/rrz0c (RZ24)...
WARNING: Unable to read data, but continuing with reassign...
scu: Verify error at logical block number 409750 (0x64096).
scu: Sense Key = 0x3 = MEDIUM ERROR - Nonrecoverable medium error,
     Sense Code/Qualifier = (0x11, 0) = Unrecovered read error
Attempting to reassign logical block 409750 on /dev/rrz0c (RZ24)...
scu> show defects grown

Displaying Grown Defect List in Physical Sector Format
   ( Defect list length is 24 bytes, containing 3 defects )

	Cylinder    742,  Head  5,  Sector   28
	Cylinder   1355,  Head  1,  Sector    9
	Cylinder   1355,  Head  1,  Sector   34
scu> 

Example of controlling auto-sense and requesting sense information:

scu> set cam flags 0x400|0x20
scu> eject
scu> tur
scu: 'test unit ready' failed, EIO (5) - I/O error
scu> zero sense
scu> show sense
Request Sense Information:

                        Error Code: 0x70 (Current Error)
                         Valid Bit: 0
                    Segment Number: 0
                         Sense Key: 0x2 (NOT READY - Logical unit is NOT ready)
                    Illegal Length: 0
                      End Of Media: 0
                         File Mark: 0
                 Information Field: 0
           Additional Sense Length: 0xa
      Command Specific Information: 0
   Additional Sense Code/Qualifier: (0x3a, 0) = Medium not present
       Field Replaceable Unit Code: 0
              Sense Specific Bytes: 00 00 00 
scu> 

Example of changing device block length:

% scu -f /dev/rrz4c
scu> show nexus
Device: RRD43, Bus: 0, Target: 4, Lun: 0, Type: Read-Only Direct Access
scu> show capacity
Disk Capacity Information:

                  Maximum Capacity: 400200 (195.410 megabytes)
                      Block Length: 512
scu> set device length 2048
scu> show capacity
Disk Capacity Information:

                  Maximum Capacity: 100050 (195.410 megabytes)
                      Block Length: 2048
scu>