The format of a SCU command is as follows:
scu>[-f device-name-path] [command[keyword]. . .]
If a device name is not specified in one of the options on the command line, the program checks the SCU_DEVICE environment variable to determine the device name. If SCU_DEVICE is not set, you must use the set nexus command to select the device and operation or some commands may be restricted.
For example, if you do not specify a device name and SCU_DEVICE is not set, you cannot format a disk because the scu utility cannot perform a mounted file system check. See Section B.3 for a description of the set command and its arguments.
If a command is not entered on the command line, the program prompts for commands until you terminate the program. In most cases, you can abbreviate commands to the lowest unambiguous number of characters.
This appendix contains an overview of the scu functions that system administrators use. Detailed information, including examples of use, is available through the online help for the scu utility. To use the help facility once you are in the scu utility, issue the help command at the scu> prompt.
B.2 SCU Utility Conventions
The following conventions describe the scu utility syntax:
| Convention | Meaning |
|---|---|
| keyword ( alias ) | Use a keyword or the specified alias. |
| address-format | Optionally accepts an address format. |
| nexus-information | Optionally accepts nexus information. |
| test-parameters | Optionally accepts test parameters. |
| D: value or string | The value or string shown is the default. |
| R: minimum-maximum | Enter a value within the range specified. |
| Format | Description |
|---|---|
| lba | Logical block address |
| msf | Minute, second, and frame |
The syntax of a command that uses the address-format parameter is as follows:
scu>[command] [address-format{lba | msf } ]
The nexus-information parameter lets users specify values to override the bus, target, and LUN values normally taken from the selected SCSI device. The nexus-information keywords are as follows:
| Parameter | Description |
|---|---|
| bus (pid) R:0-3 | SCSI bus number (path ID) |
| target (tid) R:0-7 | SCSI target number (target ID) |
| lun R:0-7 | SCSI Logical Unit Number (LUN) |
You use the test-parameter variables to specify the physical limits of the media on which the command can operate. For example, these may be the starting and ending logical block numbers on a disk. The test parameters for a command use the following syntax:
scu>command [media-limits] [test-control]
The media-limits parameter, which controls the media tested, has the following syntax:
{ lb n } { length n }
scu> command [{ starting n }] [{ endingn }] [size n]
{ limit n }
{ records n }
The alias bs (block size) is accepted for the size keyword.The test-control parameters control aspects of the test operation. The test-control parameters supported are:
{ align Align-Offset }
{ compare { on | off } }
scu> command [ { errors Error-Limit } ]
{ passes Pass-Limit }
{ pattern Data-Pattern }
{ recovery { on | off } }
The following examples show the output of the evaluate
command. Verbose mode is turned on for the first two evaluate
commands and turned off for the last one.
The following examples use the scan edt command.
The first example illustrates the command followed by the show device command to display the information resulting from the scan.
The following examples use the scan media command
with different test-parameters:
The simqueue argument issues a release SIMQ CCB to
thaw a frozen SIM queue. Ordinarily, this command is not necessary because
the SIM queue is automatically released after errors occur. If the nexus information
is omitted, the SIM queue for the selected SCSI device is released.
The following example shows the release command:
The bus argument issues a CAM Bus Reset CCB. If the
nexus information is omitted, the bus associated with the selected SCSI device
is reset. The reset bus command is restricted to superuser
(root) access because it can cause loss of data to some devices.
The device argument issues a CAM Bus Device Reset
CCB. If the nexus information is omitted, the selected device is reset. The reset device command requires write access to the selected device
because the command can cause loss of data to some devices.
If nexus information is specified, this command is restricted to the
superuser.
The media argument verifies the data written on the
device media. This activity involves reading and performing an ECC check of
the data. If the test parameters are omitted, the entire device media is verified.
If the device does not support the verify command,
the following error message appears:
When an error occurs, the sense key is examined. The expected sense
keys are Recovered Error (0x01) or Medium Error (0x03). When these errors
are detected, the following error message is displayed and verification continues
with the block following the failing block:
The following conditions apply to the verify command:
For example:
The following command changes the mode pages for a device:
change pages[mode-pages . . .] [pcf page-control-field ]
The program prompts you with a list of the page fields that are marked
as changeable. If you do not specify a mode page, all pages supported by
the device are requested for changing. After you enter the new fields for
each page, you use a mode select command to set the new page parameters.
The mode-page argument describes the mode
page to change. The mode pages are as follows:
B.3 General SCU Commands
This section
describes the general-purpose scu utility commands. For
more information on each command, see the online help that is part of the scu utility.
scu>set verbose on
scu>evaluate 0xffff
Expression Values:
Decimal: 65535
Hexadecimal: 0xffff
512 byte Blocks: 128.00
Kilobytes: 64.00
Megabytes: 0.06
Gigabytes: 0.00
scu>evaluate 64k*512
Expression Values:
Decimal: 33554432
Hexadecimal: 0x2000000
512 byte Blocks: 65536.00
Kilobytes: 32768.00
Megabytes: 32.00
Gigabytes: 0.03
scu>set verbose off
scu>evaluate 0xffff
Dec: 65525 Hex: 0xffff Blks: 128.00 Kb: 64.00 Mb: 0.06 Gb: 0.00
scu> scan edt
Scanning bus 1, target 6, lun 0, please be patient...
scu> show device
Scanning bus 1, target 6, lun 0, please be patient...
Inquiry Information:
SCSI Bus ID: 1
SCSI Target ID: 6
SCSI Target LUN: 0
Peripheral Device Type: Direct Access
Peripheral Qualifier: Peripheral Device Connected
Device Type Qualifier: 0
Removable Media: No
ANSI Version: SCSI-1 Compliant
ECMA Version: 0
ISO Version: 0
Response Data Format: CCS
Additional Length: 31
Vendor Identification: DEC
Product Identification: RZ55 (C) DEC
Firmware Revision Level: 0700
scu> scan edt bus 1
Scanning bus 1, target 6, lun 0, please be patient...
The media argument causes the device media to be
scanned. This involves writing a data pattern to the media and then reading
and verifying the data written. You must include test parameters that specify
the media area to be scanned.
scu> media
scu: No defaults, please specify test parameters for transfer
scu> scan media length 100 recovery off
Scanning 100 blocks on /dev/rrz10c (RX23) with pattern
0x39c39c39...
scu> scan media lba 200 limit 25k align 'lp-1'
Scanning 50 blocks on /dev/rrz10c (RX23) with pattern
0x39c39c39...
scu> scan media starting 0 bs 32k records 10
Scanning 640 blocks on /dev/rrz10c (RX23) with pattern
0x39c39c39...
Scanning blocks [ 0 through 63 ]...
Scanning blocks [ 64 through 127 ]...
Scanning blocks [ 128 through 191 ]...
Scanning blocks [ 192 through 255 ]...
Scanning blocks [ 256 through 319 ]...
Scanning blocks [ 320 through 383 ]...
Scanning blocks [ 384 through 447 ]...
Scanning blocks [ 448 through 511 ]...
Scanning blocks [ 512 through 575 ]...
Scanning blocks [ 576 through 639 ]...
{ audio keywords }
{ cam debug hex-flags }
{ debug { on | off } }
{ default parameter }
set { device device-type }
{ dump { on | off } }
{ dump-limit value }
{ log file-name-path }
{ nexus nexus-information }
{ pages [ mode-page [ pcf page-control-field ] }
{ pager paging-filter }
{ paging { on | off } }
{ recovery { on | off } }
{ tape keywords ... }
{ verbose { on | off } }
{ watch { on | off } }
{ audio keywords }
{ capacity }
{ defects }
{ device }
show { edt }
{ memory }
{ mode-pages }
{ nexus }
{ pages }
{ path-inquiry }
B.4 Device and Bus Management Commands
This section describes the following scu utility commands for managing SCSI devices and the CAM I/O subsystem:
scu> release simqueue bus 1 target 6 lun 0
scu>verify media starting 1000 length 1024
Verifying 1024 blocks on /dev/rrz10c (RX23),
please be patient...
Verifying blocks [ 1000 through 2023 ] ...
scu: Sense Key = 0x5 = ILLEGAL REQUEST -
Illegal request or CDB parameter,
Sense Code/Qualifier = (0x20, 0) =
Invalid command operation code
scu: Verify error at logical block number 464392 (0x71608).
scu: Sense Key = 0x1 = RECOVERED ERROR -
Recovery action performed,
Sense Code/Qualifier = (0x17, 0) = Recovered data with no
error correction applied
If any other sense key error occurs, the full sense data is displayed
and the verification process is aborted.
scu> verify media lba 464388
Verifying 1 blocks on /dev/rrz14c (RZ55),
please be patient...
Verifying blocks [ 464388 through 464388 ] ...
scu> verify media starting 640000
Verifying 9040 blocks on /dev/rrz14c (RZ55),
please be patient...
Verifying blocks [ 640000 through 649039 ] ...
scu> verify media starting 1000 length 250
Verifying 250 blocks on /dev/rrz14c (RZ55),
please be patient...
Verifying blocks [ 1000 through 1249 ] ...
scu> verify media starting 1000 ending 2000
Verifying 1001 blocks on /dev/rrz14c (RZ55),
please be patient...
Verifying blocks [ 1000 through 2000 ] ...
B.5 Device and Bus Maintenance Commands
This section describes scu utility commands for maintaining SCSI devices and the CAM I/O
subsystem.
| scu Keyword | Page Code | Description |
|---|---|---|
| error-recovery | 0x01 | Error recovery page |
| disconnect | 0x02 | Disconnect/reconnect page |
| direct-access | 0x03 | Direct access format page |
| geometry | 0x04 | Disk geometry page |
| flexible | 0x05 | Flexible disk page |
| cache-control | 0x08 | Cache control page |
| cdrom | 0x0D | CD-ROM device page |
| audio-control | 0x0E | Audio control page |
| device-configuration | 0x10 | Device configuration page |
| medium-partition-1 | 0x11 | Medium partition page 1 |
| dec-specific | 0x25 | Digital-specific page |
| readahead-control | 0x38 | Read-ahead control page |
Notes on the change pages command:
For mode pages that are unknown to the program, you can specify a hex page code for the page to change. In this mode, mode page fields are displayed and changed by hex byte values. You can also use this format to override the known formatted page change functions. For example:
change page codehex-code [pcf[page-control-field]]
The following example shows the change page command with the code parameter:
scu> change page code 0x21 Changing Unknown Page Parameters (Page 21 - current values): Byte 2 [R:0-0xff D:0x2]: 3 Byte 3 [R:0-0xff D:0x8]: Byte 4 [R:0-0xff D:0]: Byte 5 [R:0-0xff D:0]: Byte 6 [R:0-0xff D:0x3]: Byte 7 [R:0-0xff D:0xe8]: Byte 8 [R:0-0xff D:0x2]: Byte 9 [R:0-0xff D:0x96]: Byte 10 [R:0-0xff D:0x5]: scu>
The page-control-field argument specifies the type of mode pages to obtain from the device. The page control fields that you can specify are as follows:
The following example changes the error recovery parameters:
scu> change pages error Changing Error Recovery Parameters (Page 1 - current values): Disable Correction (DCR) [R:0-1 D:0]: Disable Transfer on Error (DTE) [R:0-1 D:0]: Post Recoverable Error (PER) [R:0-1 D:0]: Transfer Block (TB) [R:0-1 D:0]: Automatic Write Allocation (AWRE) [R:0-1 D:1]: Read Retry Count [R:0-255 D:8]: 25 Write Retry Count [R:0-255 D:2]: 5 scu>
downloadfilename [save] [{id buffer-id | offset offset-value | segment[ size] } ]
You can use the preceding command with any device that supports the downloading of operating software through the Write Buffer command.
The save keyword directs the device to save the new operating software in nonvolatile memory if the download command is completed successfully. With save specified, the downloaded code remains in effect after each power cycle and reset. If the save keyword is not specified, the downloaded software is placed in the control memory of the device. After a power cycle or reset, the device operation would revert to a vendor-specific condition.
If the save parameter is omitted, a Download microcode (mode 4) command is issued. Specifying save performs a Download microcode and save operation (mode 5). Not all devices accept both modes.
You can specify various parameters to control the download operation. Most devices do not require these optional parameters, but since each vendor may implement the download command differently, these parameters provide the capability to override program defaults.
The following notes apply to the download parameters:
The following notes apply to the download command:
The following examples show the download command:
scu> download ???.fup save
Downloading & Saving Firmware File '???.fup' of 131076 bytes...
scu> download ???.fup save segment
Downloading File '???.fup' of 131076 bytes in 8192 byte
segments...
Download completed successfully, now saving the microcode...
scu> download ???.fup save segment 32k
Downloading File '???.fup' of 131076 bytes in 32768 byte
segments...
Download completed successfully, now saving the microcode...
format[density density-type ] [defects defect-list ]
This command formats both hard and flexible disk media. Since this command modifies the disk media, the full command name must be entered to be recognized.
The density-type parameter specifies the density type for flexible disk media.
The defect-list parameter can be all, primary, or none. The default is to format with all known defects. If you use the default device /dev/cam to enter the scu utility and then use the set nexus command to set the device to format, the code associated with checking for mounted file systems fails. This failure avoids the possibility of accidentally formatting disks with mounted file systems.
readmedia [test-parameters]
This command performs read operations from the selected device. The command reads the device media and performs a data comparison of the data read. You must include test parameters that specify the media area to be read.
The examples that follow illustrate the use of the read command with several test-parameters:
scu> read media scu: No defaults, please specify test parameters for transfer... scu> read media lba 100 Reading 1 block on /dev/rrz10c (RX23) using pattern 0x39c39c39... scu> read media lba 100 pattern 0x12345678 Reading 1 block on /dev/rrz10c (RX23) using pattern 0x12345678... scu: Data compare error at byte position 0 scu: Data expected = 0x78, data found = 0x39 scu> read media ending 100 compare off bs 10k Reading 101 blocks on /dev/rrz10c (RX23)... Reading blocks [ 0 through 19 ]... Reading blocks [ 20 through 39 ]... Reading blocks [ 40 through 59 ]... Reading blocks [ 60 through 79 ]... Reading blocks [ 80 through 99 ]...
reassignlba logical-block
This command allows you to reassign a defective block on a disk device. Since this command modifies the disk media, the full command name must be entered to be recognized.
test[controller | drive | memory | selftest ]
This command performs tests on a controller by issuing send and receive diagnostic commands or write buffer and read buffer commands for memory testing to the selected device. If you issue the test command with no arguments, the utility performs a self test, which is supported by most controllers.
testmemory [test-parameters] [id buffer-id | mode buffer-mode | offset offset-value ]
This command verifies the controller memory by using the SCSI Read and Write Buffer commands. Since most controllers accept only the Combined Header and Data Mode with a buffer ID and buffer offset of zero, these are the defaults, but may be overridden. By default, the full memory size returned in the Read Buffer header is written/read/verified, but this too may be overridden by specifying a smaller data limit or size.
You can use various parameters to control the test memory operation. Most devices do not require these optional parameters, but newer devices may require different parameters to access the controller data buffer.
The following notes apply to the parameters used with the test memory command:
If the device does not support a Read Buffer command and/or the default parameters, an error message similar to the following is displayed:
scu> test memory
Performing Controller Memory Diagnostics...
Testing Controller Memory of 245760 bytes (Mode 0,
Offset 0)
Testing 245760 bytes on [1/2/0] (TZK11) using pattern
0x39c39c39...
scu: 'SCMD_WRITE_BUFFER' failed, EIO (5) - I/O error
scu: Sense Key = 0x5 = ILLEGAL REQUEST -
Illegal request or CDB
parameter,
Sense Code/Qualifier = (0x24, 0) =
Invalid field in cdb
The following examples show the test memory command:
% scu -f /dev/rrz11c
scu> test memory
Performing Controller Memory Diagnostics...
Testing Controller Memory of 61376 bytes (Mode 0,
Offset 0)
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0x39c39c39...
scu> test memory pattern 0x12345678 size 50k
Performing Controller Memory Diagnostics...
Testing Controller Memory of 61376 bytes (Mode 0,
Offset 0)
Testing 51200 bytes on /dev/rrz11c (RZ56) using pattern
0x12345678...
scu> test memory passes 5
Performing Controller Memory Diagnostics...
Testing Controller Memory of 61376 bytes (Mode 0,
Offset 0)
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0x39c39c39...
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0x00ff00ff...
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0x0f0f0f0f...
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0xc6dec6de...
Testing 61376 bytes on /dev/rrz11c (RZ56) using pattern
0x6db6db6d...
scu> show memory
The Controller Memory Size is 245760 (0x3c000) bytes.
scu> test memory mode 2
Performing Controller Memory Diagnostics...
Testing Controller Memory of 245760 bytes (Mode 2,
Offset 0)
Testing 245760 bytes on [1/2/0] (TZK11) using pattern
0x39c39c39...
write[media test-parameters ]
The media argument writes to the device media by using various data patterns. The patterns default to 0x39c39c39 for the first pass, 0xc6dec6de for the second, and so on as shown in the last example. You must specify transfer parameters that specify the media area to be written.
The following examples show the write media command:
scu> write media No defaults, please specify test parameters for transfer... scu> write media lba 100 Writing 1 block on /dev/rrz10c (RX23) with pattern 0x39c39c39... scu> write media starting 100 ending 250 Writing 151 blocks on /dev/rrz10c (RX23) with pattern 0x39c39c39... scu> write media starting 2800 limit 1m bs 10k Writing 80 blocks on /dev/rrz10c (RX23) with pattern 0x39c39c39... Writing blocks [ 2800 through 2819 ]... Writing blocks [ 2820 through 2839 ]... Writing blocks [ 2840 through 2859 ]... Writing blocks [ 2860 through 2879 ]... scu> write media lba 2879 passes 5 Writing 1 block on /dev/rrz10c (RX23) with pattern 0x39c39c39... Writing 1 block on /dev/rrz10c (RX23) with pattern 0xc6dec6de... Writing 1 block on /dev/rrz10c (RX23) with pattern 0x6db6db6d... Writing 1 block on /dev/rrz10c (RX23) with pattern 0x00000000... Writing 1 block on /dev/rrz10c (RX23) with pattern 0xffffffff...