Changes For This Release

• An option has been added to allow random I/O to be selected instead of the default sequential I/O. This is accomplished via:

  	iotype=type	Set I/O type to: {random or sequential}.
  

  The seeks are limited to the data limited specified or calculated from the dt command line. If data limits aren't specified, seeks are limited to the size of existing files, or to the entire disk (obtained via ioctl() Digital Unix for raw devices). If the data limits exceed the capacity of the media/partition/file under test, a premature end-of-file will be encountered on reads or writes.

• An option was added to control checking of inverted data bytes when doing long reads of short tape records. Previously, certain DME's would transfer garbage data at the end of short records, but since this garbage is not included in the read() count returned, is not normally accessed by programs, and does not exceed users' buffers, this was deemed acceptable. [ Reference QAR 40101 for more information. ]

  By default, this check is now disabled, but can be re-enabled via the "enable=spad" option (short pad check) if desired.

• Makefile and source conditionalized so dt now builds on LINUX.

The latest version of dt is available on our production machines in the following account:

Last modified: February 22, 1996

Examples:

% disklabel rz8c
Invalid disk label (label is corrupted, or disk is unlabeled)
% scu -f /dev/rrz8c show capacity

Disk Capacity Information:

                  Maximum Capacity: 1046206 (510.843 megabytes)
                      Block Length: 512

% dt of=/dev/rrz8c bs=64k limit=100m iotype=random
Write Statistics:
     Total records processed: 1600 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 104857600 (102400.000 Kbytes, 100.000 Mbytes)
      Average transfer rates: 1703617 bytes/sec, 1663.688 Kbytes/sec
      Total passes completed: 0/1
       Total errors detected: 0/1
          Total elapsed time: 01m01.55s
           Total system time: 00m00.36s
             Total user time: 00m07.16s

Read Statistics:
     Total records processed: 1600 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 104857600 (102400.000 Kbytes, 100.000 Mbytes)
      Average transfer rates: 1344616 bytes/sec, 1313.101 Kbytes/sec
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 01m17.98s
           Total system time: 00m00.35s
             Total user time: 00m25.36s

Total Statistics:
     Output device/file name: /dev/rrz8c (Device: RZ25M, type=disk)
   Data pattern read/written: 0x39c39c39
     Total records processed: 3200 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 209715200 (204800.000 Kbytes, 200.000 Mbytes)
      Average transfer rates: 1502796 bytes/sec, 1467.574 Kbytes/sec
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 02m19.55s
           Total system time: 00m00.71s
             Total user time: 00m32.53s
               Starting time: Fri Feb 23 16:10:46 1996
                 Ending time: Fri Feb 23 16:13:05 1996

% dt if=/dev/rrz8c bs=64k records=10 iotype=random disable=compare enable=Debug
dt: Attempting to open input file '/dev/rrz8c', mode = 00...
dt: Input file '/dev/rrz8c' successfully opened, fd = 3
dt: Allocated buffer at address 0x140014000 of 65540 bytes, using offset 0
dt: Seeking to random block 951 at byte position 486912...
dt: Record #1, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 953 at byte position 487936...
dt: Record #2, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 818 at byte position 418816...
dt: Record #3, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 124 at byte position 63488...
dt: Record #4, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 664 at byte position 339968...
dt: Record #5, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 70 at byte position 35840...
dt: Record #6, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 68 at byte position 34816...
dt: Record #7, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 206 at byte position 105472...
dt: Record #8, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 444 at byte position 227328...
dt: Record #9, Reading 65536 bytes into buffer at address 0x140014000...
dt: Seeking to random block 914 at byte position 467968...
dt: Record #10, Reading 65536 bytes into buffer at address 0x140014000...
Total Statistics:
      Input device/file name: /dev/rrz8c (Device: RZ25M, type=disk)
           Data pattern read: 0x39c39c39 (data compare disabled)
     Total records processed: 10 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 655360 (640.000 Kbytes, 0.625 Mbytes)
      Average transfer rates: 1572864 bytes/sec, 1536.000 Kbytes/sec
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.41s
           Total system time: 00m00.00s
             Total user time: 00m00.00s
               Starting time: Fri Feb 23 16:13:47 1996
                 Ending time: Fri Feb 23 16:13:48 1996

dt: Closing file '/dev/rrz8c', fd = 3...
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