Data Test Program (dt) February 2nd, 2001

What's New as of February 2nd, 2001

Changes For This Release

This is a major release of dt. Many new features have been added, and the code has been restructured quite a bit to accomodate these changes and future enhancements.

The following changes were made to dt Version 14.0:

Slice & Dice: A powerful new option (IMHO) has been added for random access devices. A slices=value option was added which divides the media into slices. Each slice contains a a range of blocks to operate on. If no pattern is specified, each slice is started with a different data pattern. Each subsequent pass alternates through the 12 internal patterns.
Furthermore, each slice can have multiple processes and/or async I/O's (aios=value). So with a single command, you can generate a very heavy I/O load, great for stress testing!
Note: AIO is only supported on Tru64 Unix and SCO UnixWare.
You can now enable variable length request sizes, by using incr=var{iable} with the min/max= options. The request size calcualated will (of course) be between the min/max values and be device size bytes aligned. (see example below)
It is now possible to specify the I/O direction for random access devices (disks, CD-ROM's, file system, etc). The new iodir={forward,reverse} option controls this. When reverse I/O reaches the beginning of media, dt will exit with 254, which is its' normal end of file (EOF) status code.
Random I/O options (iotype=random or iodir=reverse) is now supported with regular files (i.e., files on a file system). The only caveat is that you must specify a data limit using the limit/records= options, since my find capacity algorthm won't work with regular files :-)
The hard coded 512 byte blocking previously imposed with the IOT test pattern (pattern=iot) has been lifted. The blocking used is setup from 1) dsize=value option, 2) lbs=value option, 3) device IOCTL (Tru64 only), or 4) defaults to 512 bytes. This restriction was lifted, since the Windows IOT test discs are blocked at 2048 bytes (native CD-ROM 2K block size).
Windows enhancements were made to recognize physical devices and Cygnus mounted tape names (/dev/rmtN and /dev/nrmtN), which is necessary for proper tape operation.
The "volumes=" and "vrecords=" options have been added to aid with multi-volume testing, esp. for tapes. With these options you simply tell dt how many volumes to write, and the number of records to write on the last volume. This resolves capacity guessing problems with tapes, where data compression and varying media capacities, were problematic for our test scripts.
Also Note: After changing media and continuing, if using a tape device, a rewind operation is performed to ensure the device is ready before continuing. This latter check is esp. important when changing tapes on Linux and Windows.
Additional checking to catch illegal or dangerous combinations of options. For example, for IOT or Lbdata options, the block size must be greater than sizeof(u_int32), which is the size of the lba encoded at the beginning of each record.
Better sanity checking for random access device options. The major checks in this area are to ensure block sizes are modulo the device size. This additional checking can be bypassed by using the new "enable=bypass" option (this latter option may by of interest to those of you on Tru64 Unix doing non-modulo disk block access). In general, these sanity checks prevent unexpected test failures.
When using multiple processes (procs=) with regular files, a different pattern is used for each file, unless you specify a pattern to use. Use the disable=unique to avoid this action. This pattern usage is consistent with that implemented with The new slices= option (i.e. different pattern for each slice).
The "rseed=value" no longer enabled random I/O automatically. This option simply sets the random number generator seed now, since this option is necessary for variable request sizes too.
When "enable=Debug" is specified, when using rotating media or the IOT/Lbdata options, the lba is now reported with record information.
Extended statistics are reported when random I/O and/or slices options were specified.
When aborting child processes, a SIGINT is now sent instead of SIGTERM, so the child process can report its' statistics. This was important for long running tests. If SIGINT is problematic, I'll add an option to specify the kill signal.
Some functions were converted to macros to inline code, which hopefully improves performance a little.
Existing output files are no longer deleted automatically. Only files created by dt get deleted. Use dispose=delete, *if* you want existing output files deleted.
When using multiple slices to an existing output file, the file is *not* deleted to avoid races with multiple procs.

Please see attached examples for use of these new options.

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

http://www.zk3.dec.com/~rmiller/dt.html or http://leto.shr.dec.com/~rmiller/dt.html

External to Compaq, you can obtain dt kits from URL:

http://www.bit-net.com/~rmiller/dt.html

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

To Robin's home page.

Last modified: February 2nd, 2001

Examples:

tru64% dt of=/dev/rrz1c bs=256k capacity=12g limit=1m slices=12 enable=debug,lbdata,raw
dt: Data limit set to 12884901888 bytes (12288.000 Mbytes), 25165824 blocks.
dt: Started process 18122...
dt: Started process 18121...
dt: Started process 18127...
dt: Started process 18126...
dt: Started process 18128...
dt: Started process 18115...
dt: Started process 18133...
dt: Started process 18134...
dt: Started process 18132...
dt: Started process 18131...
dt (18122): Start Position 0 (lba 0), Limit 1048576, Pattern 0x39c39c39
dt (18122): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18121): Start Position 1073741824 (lba 2097152), Limit 1048576 bytes
dt (18121): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18127): Start Position 2147483648 (lba 4194304), Limit 1048576 bytes
dt (18127): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18126): Start Position 3221225472 (lba 6291456), Limit 1048576 bytes
dt (18126): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18128): Start Position 4294967296 (lba 8388608), Limit 1048576 bytes
dt (18128): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18115): Start Position 5368709120 (lba 10485760), Limit 1048576 bytes
dt (18115): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18133): Start Position 6442450944 (lba 12582912), Limit 1048576 bytes
dt (18133): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18134): Start Position 7516192768 (lba 14680064), Limit 1048576 bytes
dt (18134): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18132): Start Position 8589934592 (lba 16777216), Limit 1048576 bytes
dt (18132): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt (18131): Start Position 9663676416 (lba 18874368), Limit 1048576 bytes
dt (18131): Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
		.
		.
		.
Total Statistics (18138):
     Output device/file name: /dev/rrz1c (Device: BB01811C, type=disk)
     Type of I/O's performed: sequential (forward, read-after-write)
      Slice Range Parameters: position=11811160064 (lba 23068672), limit=1048576
      Current Slice Reported: 12/12
   Data pattern read/written: 0xffffffff (w/lbdata, lba 0, size 512 bytes)
     Total records processed: 8 @ 262144 bytes/record (256.000 Kbytes)
     Total bytes transferred: 2097152 (2048.000 Kbytes, 2.000 Mbytes)
      Average transfer rates: 1797559 bytes/sec, 1755.429 Kbytes/sec
     Number I/O's per second: 6.857
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m01.16s
           Total system time: 00m00.00s
             Total user time: 00m00.05s
               Starting time: Mon Jan 29 14:38:49 2001
                 Ending time: Mon Jan 29 14:38:51 2001

dt: Child process 18138, exiting with status 0
tru64% 


tru64% dt of=/dev/rrz1c bs=64k capacity=10g procs=2 slices=4 enable=debug,lbdata
dt (21933): Data limit set to 10737418240 bytes (10240.000 Mbytes), 20971520 blocks.
dt: Started process 21930...
dt: Started process 21937...
dt: Started process 21938...
dt: Started process 21939...
dt: Waiting for 4 child processes to complete...
dt (21930): Start Position 0 (lba 0), Limit 2684354560 bytes
dt: Started process 21940...
dt: Started process 21936...
dt: Started process 21935...
dt: Started process 21942...
dt: Waiting for 4 child processes to complete...
dt (21937): Start Position 2684354560 (lba 5242880), Limit 2684354560 bytes
dt: Started process 21943...
dt: Started process 21941...
dt: Started process 21946...
dt: Started process 21947...
dt: Waiting for 4 child processes to complete...
dt (21938): Start Position 5368709120 (lba 10485760), Limit 2684354560 bytes
dt: Started process 21945...
dt: Started process 21953...
dt: Started process 21954...
dt: Started process 21956...
dt: Waiting for 4 child processes to complete...
dt (21939): Start Position 8053063680 (lba 15728640), Limit 2684354560 bytes
dt: Started process 21955...
dt: Started process 21952...
dt: Started process 21951...
dt: Started process 21950...
dt: Waiting for 4 child processes to complete...
dt (21940): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21936): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21935): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21942): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21943): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21941): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21946): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21947): Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt (21940): Output file '/dev/rrz1c' successfully opened, fd = 3
		.
		.
		.
Total Statistics (21942):
     Output device/file name: /dev/rrz1c (Device: BB01811C, type=disk)
     Type of I/O's performed: sequential (forward)
    Current Process Reported: 4/4
   Data pattern read/written: 0x39c39c39 (w/lbdata, lba 0, size 512 bytes)
     Total records processed: 81920 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 5368709120 (5242880.000 Kbytes, 5120.000 Mbytes)
      Average transfer rates: 464246 bytes/sec, 453.365 Kbytes/sec
     Number I/O's per second: 7.084
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 3h12m44.36s
           Total system time: 00m13.71s
             Total user time: 04m49.36s
               Starting time: Tue Jan 30 08:51:00 2001
                 Ending time: Tue Jan 30 12:03:44 2001

dt: Child process 21942, exiting with status 0
dt: Child process 21930, exiting with status 0
tru64% 


tru64% dt of=/dev/rrz1c min=4k max=256k incr=variable enable=Debug,lbdata disable=pstats count=3
dt: Attempting to open output file '/dev/rrz1c', open flags = 01 (0x1)...
dt: Output file '/dev/rrz1c' successfully opened, fd = 3
dt: Allocated buffer at address 0x140036000 of 262148 bytes, using offset 0
dt: Record #1 (lba 0), Writing 4096 bytes from buffer 0x140036000...
dt: Record #2 (lba 8), Writing 235520 bytes from buffer 0x140036000...
dt: Record #3 (lba 468), Writing 225280 bytes from buffer 0x140036000...
dt: End of Write pass 0, records = 3, errors = 0, elapsed time = 00m00.05s
dt: Closing file '/dev/rrz1c', fd = 3...
dt: Attempting to reopen file '/dev/rrz1c', open flags = 00 (0)...
dt: File '/dev/rrz1c' successfully reopened, fd = 3
dt: Record #1 (lba 0), Reading 4096 bytes into buffer 0x140036000...
dt: Record #2 (lba 8), Reading 235520 bytes into buffer 0x140036000...
dt: Record #3 (lba 468), Reading 225280 bytes into buffer 0x140036000...
dt: End of Read pass 1, records = 3, errors = 0, elapsed time = 00m00.10s
dt: Closing file '/dev/rrz1c', fd = 3...

Total Statistics:
     Output device/file name: /dev/rrz1c (Device: BB01811C, type=disk)
     Type of I/O's performed: sequential (forward, rseed=0xf41e15)
   Data pattern read/written: 0x39c39c39 (w/lbdata, lba 0, size 512 bytes)
     Total records processed: 6 with min=4096, max=262144, incr=variable
     Total bytes transferred: 929792 (908.000 Kbytes, 0.887 Mbytes)
      Average transfer rates: 6198613 bytes/sec, 6053.333 Kbytes/sec
     Number I/O's per second: 40.000
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.15s
           Total system time: 00m00.00s
             Total user time: 00m00.06s
               Starting time: Mon Jan 29 14:30:08 2001
                 Ending time: Mon Jan 29 14:30:08 2001

tru64% 


tru64% dt of=/dev/rrz1c bs=256k capacity=1m enable=Debug,lbdata,raw iodir=reverse
dt: Attempting to open output file '/dev/rrz1c', open flags = 02 (0x2)...
dt: Output file '/dev/rrz1c' successfully opened, fd = 3
dt: Random data limit set to 1048576 bytes (1.000 Mbytes), 2048 blocks.
dt: Allocated buffer at address 0x140036000 of 262148 bytes, using offset 0
dt: Allocated buffer at address 0x140078000 of 262148 bytes, using offset 0
dt: Seeked to block 2048 (0x800) at byte position 1048576.
dt: Seeked to block 1536 (0x600) at byte position 786432.
dt: Record #1 (lba 1536), Writing 262144 bytes from buffer 0x140078000...
dt: Seeked to block 1536 (0x600) at byte position 786432.
dt: Record #1 (lba 1536), Reading 262144 bytes into buffer 0x140036000...
dt: Seeked to block 1024 (0x400) at byte position 524288.
dt: Record #2 (lba 1024), Writing 262144 bytes from buffer 0x140078000...
dt: Seeked to block 1024 (0x400) at byte position 524288.
dt: Record #2 (lba 1024), Reading 262144 bytes into buffer 0x140036000...
dt: Seeked to block 512 (0x200) at byte position 262144.
dt: Record #3 (lba 512), Writing 262144 bytes from buffer 0x140078000...
dt: Seeked to block 512 (0x200) at byte position 262144.
dt: Record #3 (lba 512), Reading 262144 bytes into buffer 0x140036000...
dt: Seeked to block 0 (0) at byte position 0.
dt: Record #4 (lba 0), Writing 262144 bytes from buffer 0x140078000...
dt: Seeked to block 0 (0) at byte position 0.
dt: Record #4 (lba 0), Reading 262144 bytes into buffer 0x140036000...
dt: Beginning of media detected [file #1, record #4]
dt: Exiting with status code 254...
dt: Closing file '/dev/rrz1c', fd = 3...

Total Statistics:
     Output device/file name: /dev/rrz1c (Device: BB01811C, type=disk)
     Type of I/O's performed: sequential (reverse, read-after-write)
   Data pattern read/written: 0x39c39c39 (w/lbdata, lba 0, size 512 bytes)
     Total records processed: 8 @ 262144 bytes/record (256.000 Kbytes)
     Total bytes transferred: 2097152 (2048.000 Kbytes, 2.000 Mbytes)
      Average transfer rates: 9679163 bytes/sec, 9452.308 Kbytes/sec
     Number I/O's per second: 36.923
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.21s
           Total system time: 00m00.00s
             Total user time: 00m00.05s
               Starting time: Mon Jan 29 14:36:36 2001
                 Ending time: Mon Jan 29 14:36:37 2001

tru64% 


tru64% dt of=/usr/tmp/dt.data bs=256k iotype=random procs=2 limit=1m enable=Debug disable=pstats
dt: Started process 18206...
dt: Started process 18207...
dt: Waiting for 2 child processes to complete...
dt (18206): Attempting to open output file '/usr/tmp/dt.data-18206', open flags = 01001 (0x201)...
dt (18206): Output file '/usr/tmp/dt.data-18206' successfully opened, fd = 3
dt (18206): Random data limit set to 1048576 bytes (1.000 Mbytes), 2048 blocks.
dt (18206): Allocated buffer at address 0x14003e000 of 262148 bytes, using offset 0
dt (18206): Seeked to block 309 (0x135) at byte position 158208.
dt (18207): Attempting to open output file '/usr/tmp/dt.data-18207', open flags = 01001 (0x201)...
dt (18207): Output file '/usr/tmp/dt.data-18207' successfully opened, fd = 3
dt (18207): Random data limit set to 1048576 bytes (1.000 Mbytes), 2048 blocks.
dt (18207): Allocated buffer at address 0x14003e000 of 262148 bytes, using offset 0
dt (18207): Seeked to block 424 (0x1a8) at byte position 217088.
dt (18206): Record #1 (lba 309), Writing 262144 bytes from buffer 0x14003e000...
dt (18206): Seeked to block 1023 (0x3ff) at byte position 523776.
dt (18207): Record #1 (lba 424), Writing 262144 bytes from buffer 0x14003e000...
dt (18207): Seeked to block 104 (0x68) at byte position 53248.
dt (18206): Record #2 (lba 1023), Writing 262144 bytes from buffer 0x14003e000...
dt (18206): Seeked to block 496 (0x1f0) at byte position 253952.
dt (18207): Record #2 (lba 104), Writing 262144 bytes from buffer 0x14003e000...
dt (18207): Seeked to block 338 (0x152) at byte position 173056.
dt (18207): Record #3 (lba 338), Writing 262144 bytes from buffer 0x14003e000...
dt (18206): Record #3 (lba 496), Writing 262144 bytes from buffer 0x14003e000...
dt (18206): Seeked to block 360 (0x168) at byte position 184320.
dt (18207): Seeked to block 121 (0x79) at byte position 61952.
dt (18207): Record #4 (lba 121), Writing 262144 bytes from buffer 0x14003e000...
dt (18207): Flushing data to file '/usr/tmp/dt.data-18207'...
dt (18206): Record #4 (lba 360), Writing 262144 bytes from buffer 0x14003e000...
dt (18206): Flushing data to file '/usr/tmp/dt.data-18206'...
dt (18207): End of Write pass 0, records = 4, errors = 0, elapsed time = 00m00.23s
dt (18207): Closing file '/usr/tmp/dt.data-18207', fd = 3...
dt (18207): Attempting to reopen file '/usr/tmp/dt.data-18207', open flags = 00 (0)...
dt (18207): File '/usr/tmp/dt.data-18207' successfully reopened, fd = 3
dt (18207): Seeked to block 424 (0x1a8) at byte position 217088.
dt (18207): Record #1 (lba 424), Reading 262144 bytes into buffer 0x14003e000...
dt (18206): End of Write pass 0, records = 4, errors = 0, elapsed time = 00m00.25s
dt (18206): Closing file '/usr/tmp/dt.data-18206', fd = 3...
dt (18206): Attempting to reopen file '/usr/tmp/dt.data-18206', open flags = 00 (0)...
dt (18206): File '/usr/tmp/dt.data-18206' successfully reopened, fd = 3
dt (18206): Seeked to block 309 (0x135) at byte position 158208.
dt (18206): Record #1 (lba 309), Reading 262144 bytes into buffer 0x14003e000...
dt (18206): Seeked to block 1023 (0x3ff) at byte position 523776.
dt (18206): Record #2 (lba 1023), Reading 262144 bytes into buffer 0x14003e000...
dt (18207): Seeked to block 104 (0x68) at byte position 53248.
dt (18207): Record #2 (lba 104), Reading 262144 bytes into buffer 0x14003e000...
dt (18206): Seeked to block 496 (0x1f0) at byte position 253952.
dt (18206): Record #3 (lba 496), Reading 262144 bytes into buffer 0x14003e000...
dt (18207): Seeked to block 338 (0x152) at byte position 173056.
dt (18207): Record #3 (lba 338), Reading 262144 bytes into buffer 0x14003e000...
dt (18206): Seeked to block 360 (0x168) at byte position 184320.
dt (18206): Record #4 (lba 360), Reading 262144 bytes into buffer 0x14003e000...
dt (18207): Seeked to block 121 (0x79) at byte position 61952.
dt (18207): Record #4 (lba 121), Reading 262144 bytes into buffer 0x14003e000...
dt (18206): End of Read pass 1, records = 4, errors = 0, elapsed time = 00m00.15s
dt (18206): Closing file '/usr/tmp/dt.data-18206', fd = 3...

Total Statistics (18206):
     Output device/file name: /usr/tmp/dt.data-18206 (device type=regular)
     Type of I/O's performed: random (rseed=0xf594ce)
       Random I/O Parameters: position=0, ralign=0, rlimit=1048576
    Current Process Reported: 1/2
   Data pattern read/written: 0x39c39c39
     Total records processed: 8 @ 262144 bytes/record (256.000 Kbytes)
     Total bytes transferred: 2097152 (2048.000 Kbytes, 2.000 Mbytes)
      Average transfer rates: 5033165 bytes/sec, 4915.200 Kbytes/sec
     Number I/O's per second: 19.200
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.41s
           Total system time: 00m00.03s
             Total user time: 00m00.08s
               Starting time: Mon Jan 29 14:56:44 2001
                 Ending time: Mon Jan 29 14:56:45 2001

dt (18207): End of Read pass 1, records = 4, errors = 0, elapsed time = 00m00.16s
dt (18207): Closing file '/usr/tmp/dt.data-18207', fd = 3...

Total Statistics (18207):
     Output device/file name: /usr/tmp/dt.data-18207 (device type=regular)
     Type of I/O's performed: random (rseed=0xf594d0)
       Random I/O Parameters: position=0, ralign=0, rlimit=1048576
    Current Process Reported: 2/2
   Data pattern read/written: 0x00ff00ff
     Total records processed: 8 @ 262144 bytes/record (256.000 Kbytes)
     Total bytes transferred: 2097152 (2048.000 Kbytes, 2.000 Mbytes)
      Average transfer rates: 5242880 bytes/sec, 5120.000 Kbytes/sec
     Number I/O's per second: 20.000
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.40s
           Total system time: 00m00.01s
             Total user time: 00m00.08s
               Starting time: Mon Jan 29 14:56:44 2001
                 Ending time: Mon Jan 29 14:56:45 2001

dt: Child process 18207, exiting with status 0
dt: Child process 18206, exiting with status 0
tru64% 


Ok, so I didn't have a tape drive for testing :-)
-------------------------------------------------

tru64% dt of=/dev/rfd0c bs=32k volumes=2 enable=lbdata vrecords=5 aios=4

Please insert volume #2 in drive /dev/rfd0c, press ENTER when ready to proceed: 
    [ Continuing at record #46, bytes written so far 1474560... ]

Write Statistics:
     Total records processed: 50 @ 32768 bytes/record (32.000 Kbytes)
     Total bytes transferred: 1638400 (1600.000 Kbytes, 1.562 Mbytes)
      Average transfer rates: 8004 bytes/sec, 7.816 Kbytes/sec
     Number I/O's per second: 0.244
     Total volumes completed: 2/2
      Total passes completed: 0/1
       Total errors detected: 0/1
          Total elapsed time: 03m24.70s
           Total system time: 00m00.00s
             Total user time: 00m00.01s

Please insert volume #1 in drive /dev/rfd0c, press ENTER when ready to proceed: 

Please insert volume #2 in drive /dev/rfd0c, press ENTER when ready to proceed: 
    [ Continuing at record #46, bytes read so far 1474560... ]

Read Statistics:
     Total records processed: 50 @ 32768 bytes/record (32.000 Kbytes)
     Total bytes transferred: 1638400 (1600.000 Kbytes, 1.562 Mbytes)
      Average transfer rates: 13859 bytes/sec, 13.534 Kbytes/sec
     Number I/O's per second: 0.423
     Total volumes completed: 2/2
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 01m58.21s
           Total system time: 00m00.01s
             Total user time: 00m00.16s

Total Statistics:
     Output device/file name: /dev/rfd0c (Device: floppy, type=disk)
     Type of I/O's performed: sequential
   Data pattern read/written: 0x39c39c39 (w/lbdata, lba 0, size 512 bytes)
     Total records processed: 100 @ 32768 bytes/record (32.000 Kbytes)
     Total bytes transferred: 3276800 (3200.000 Kbytes, 3.125 Mbytes)
      Average transfer rates: 9373 bytes/sec, 9.153 Kbytes/sec
     Asynchronous I/O's used: 4
     Number I/O's per second: 0.286
     Total volumes completed: 2/2
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 05m49.61s
           Total system time: 00m00.01s
             Total user time: 00m00.18s
               Starting time: Mon Jan 15 13:56:41 2001
                 Ending time: Mon Jan 15 14:02:30 2001

tru64% 


meda# ./dt if=e:iot.iot bs=64k pattern=iot dsize=2k limit=1m

Total Statistics:
      Input device/file name: e:iot.iot
     Type of I/O's performed: sequential
    Data pattern string used: 'IOT Pattern' (blocking is 2048 bytes)
     Total records processed: 16 @ 65536 bytes/record (64.000 Kbytes)
     Total bytes transferred: 1048576 (1024.000 Kbytes, 1.000 Mbytes)
      Average transfer rates: 1398101 bytes/sec, 1365.333 Kbytes/sec
     Number I/O's per second: 21.333
      Total passes completed: 1/1
       Total errors detected: 0/1
          Total elapsed time: 00m00.75s
           Total system time: 00m00.01s
             Total user time: 00m00.07s
               Starting time: Mon Jan 29 14:33:49 2001
                 Ending time: Mon Jan 29 14:33:55 2001

meda#