Data Test Program (dt)

What Is this Program Used For?

dt is a generic data test program used to verify proper operation of peripherals, file systems, device drivers, or any data stream supported by the operating system. In its' simplest mode of operation, dt writes and then verifys its' default data pattern, then displays performance statisics and other test parameters before exiting. Since verification of data is performed, dt can be thought of as a generic diagnostic tool.

dt is conditionalized to run on Tru64 UNIX, HP-UX, AIX, Solaris, ULTRIX, OSF/MK, QNX, Linux, SCO Unixware, and Windows operating systems. The Windows version requires the Cygnus Solutions cygwin toolkit.

dt command lines are similar to the dd program, which is popular on most UNIX systems. It contains numerous options to give the user control of various test parameters.

dt has been used to successfully test disks, tapes, serial lines, parallel lines, pipes, and memory mapped files. In fact, dt can be used for any device that allows the standard open, read, write, and close system calls. Special support is necessary for some devices, such as serial lines, for setting up the speed, parity, data bits, etc.

Latest dt Kits:

Latest dt source kit Version
dt Program Overview (Acrobat .pdf).
dt Program Overview (PowerPoint).
dt User's Manual (Acrobat .pdf)
dt User's Manual (Postscript).
Digital Unix V3.2x dt executable.
Tru64 Unix V4.0x dt executable.
TruCluster Wave V1.6 dt executable.
TruCluster Wave 4.x dt executable.
Tru64 Unix V5.x dt executable.
Windows/NT Data Test Program dt Kit.
Linux Alpha Data Test Program dt Kit.
Linux Intel Data Test Program dt Kit.
FreeBSD 4.0 Data Test Program dt Kit..
SCO UnixWare 7.1 Data Test Program dt Kit.
HP-UX IA64 dt executable.
HP-UX PA-RISC dt executable.
Unpack the above archives via: "gzip -dc kit-name.tar.gz | tar xvf -"

Please Note:While the latest dt source is Version 15.14, only the latest operating system releases are kept up to date. Rebuilding dt is fairly easy. Copy the necessary Makefile, then follow these steps to build:

        % cp -p Makefile.linux Makefile
        % make clean ; make

Latest Changes:

What's New as of August 14th, 2004 (Version 15.10)
What's New as of March 25th, 2003 (Version 14.28)
What's New as of January 29th, 2001 (Version 14.2)
What's New as of April 2nd, 2000 (Version 13.10)
What's New as of January 12th, 2000 (Version 13.0)
What's New as of November 11th, 1999 (Version 12.10)
What's New as of August 2nd, 1999 (Version 12.3)
What's New as of January 13th, 1999 (Version 11.3)
What's New as of April 8th, 1998 (Version 10.15)
What's New as of January 28th, 1998 (Version 10.12)
What's New as of May 14th, 1997 (Version 10.8)
What's New as of March 30th, 1996 (Version 10.2)
What's New as of February 21st, 1996 (Version 9.4)
What's New as of December 9th, 1995 (Version 9.0)
What's New as of July 27th, 1995 (Version 8.0)

For issues with this web site send mail to:
For questions about dt itself, send mail to:

Last modified: April 11th, 2007

Uses For dt:

Those people with an imagination can find many uses for dt, but I'll list a few just to whet your appetite: Although I've started to add specific testing of serial lines with modem control, this support is incomplete and untested.

I hope you find dt as useful as I have. This is usually one of the first tools I port to a new operating system, since it's an excellent diagnostic and performance tool.

Help Text:

% dt help

% Usage: dt options...

    Where options are:
        if=filename      The input file to read.
        of=filename      The output file to write.
        pf=filename      The data pattern file to use.
        bs=value         The block size to read/write.
        log=filename     The log file name to write.
        munsa=string     Set munsa to: cr, cw, pr, pw, ex.
        aios=value       Set number of AIO's to queue.
        align=offset     Set offset within page aligned buffer.
    or  align=rotate     Rotate data address through sizeof(ptr).
        capacity=value   Set the device capacity in bytes.
    or  capacity=max     Set maximum capacity from disk driver.
        dispose=mode     Set file dispose to: {delete or keep}.
        dlimit=value     Set the dump data buffer limit.
        dtype=string     Set the device type being tested.
        idtype=string    Set input device type being tested.
        odtype=string    Set output device type being tested.
        dsize=value      Set the device block (sector) size.
        errors=value     The number of errors to tolerate.
        files=value      Set number of tape files to process.
        flow=type        Set flow to: none, cts_rts, or xon_xoff.
        incr=value       Set number of record bytes to increment.
    or  incr=variable    Enables variable I/O request sizes.
        iodir=direction  Set I/O direction to: {forward or reverse}.
        iomode=mode      Set I/O mode to: {copy, test, or verify}.
        iotype=type      Set I/O type to: {random or sequential}.
        min=value        Set the minumum record size to transfer.
        max=value        Set the maximum record size to transfer.
        lba=value        Set starting block used w/lbdata option.
        lbs=value        Set logical block size for lbdata option.
        limit=value      The number of bytes to transfer.
        flags=flags      Set open flags:   {excl,sync,...}
        oflags=flags     Set output flags: {append,trunc,...}
        oncerr=action    Set child error action: {abort or continue}.
        parity=string    Set parity to: {even, odd, or none}.
        passes=value     The number of passes to perform.
        pattern=value    The 32 bit hex data pattern to use.
    or  pattern=iot      Use DJ's IOT test pattern.
    or  pattern=incr     Use an incrementing data pattern.
    or  pattern=string   The string to use for the data pattern.
        position=offset  Position to offset before testing.
        procs=value      The number of processes to create.
        ralign=value     The random I/O offset alignment.
        rlimit=value     The random I/O data byte limit.
        rseed=value      The random number generator seed.
        records=value    The number of records to process.
        runtime=time     The number of seconds to execute.
        slice=value      The specific disk slice to test.
        slices=value     The number of disk slices to test.
        skip=value       The number of records to skip past.
        seek=value       The number of records to seek past.
        step=value       The number of bytes seeked after I/O.
        speed=value      The tty speed (baud rate) to use.
        timeout=value    The tty read timeout in .10 seconds.
        ttymin=value     The tty read minimum count (sets vmin).
        trigger=type     The trigger to execute during errors.
        volumes=value    The number of volumes to process.
        vrecords=value   The record limit for the last volume.
        enable=flag      Enable one or more of the flags below.
        disable=flag     Disable one or more of the flags below.

    Flags to enable/disable:
        aio              POSIX Asynchronous I/O.(Default: disabled)
        cerrors          Report close errors.   (Default: enabled)
        compare          Data comparison.       (Default: enabled)
        coredump         Core dump on errors.   (Default: disabled)
        debug            Debug output.          (Default: disabled)
        Debug            Verbose debug output.  (Default: disabled)
        rdebug           Random debug output.   (Default: disabled)
        diag             Log diagnostic msgs.   (Default: disabled)
        dump             Dump data buffer.      (Default: enabled)
        eof              EOF/EOM exit status.   (Default: enabled)
        eei              Tape EEI reporting.    (Default: enabled)
        resets           Tape reset handling.   (Default: disabled)
        fsalign          File system align.     (Default: disabled)
        flush            Flush tty I/O queues.  (Default: enabled)
        fsync            Controls file sync'ing.(Default: runtime)
        header           Log file header.       (Default: enabled)
        lbdata           Logical block data.    (Default: disabled)
        loopback         Loopback mode.         (Default: disabled)
        microdelay       Microsecond delays.    (Default: disabled)
        mmap             Memory mapped I/O.     (Default: disabled)
        modem            Test modem tty lines.  (Default: disabled)
        multi            Multiple volumes.      (Default: disabled)
        pstats           Per pass statistics.   (Default: enabled)
        raw              Read after write.      (Default: disabled)
        stats            Display statistics.    (Default: enabled)
        table            Table(sysinfo) timing. (Default: disabled)
        ttyport          Flag device as a tty.  (Default: disabled)
        unique           Unique pattern.        (Default: enabled)
        verbose          Verbose output.        (Default: enabled)
        verify           Verify data written.   (Default: enabled)

        Example: enable=debug disable=compare,pstats

    MUNSA Lock Options:
        cr = Concurrent Read (permits read access, cr/pr/cw by others)
        pr = Protected Read (permits cr/pr read access to all, no write)
        cw = Concurrent Write (permits write and cr access to resource by all)
        pw = Protected Write (permits write access, cr by others)
        ex = Exclusive Mode (permits read/write access, no access to others)

            For more details, please refer to the dlm(4) reference page.

    Common Open Flags:
        excl (O_EXCL)         Exclusive open. (don't share)
        ndelay (O_NDELAY)     Non-delay open. (don't block)
        nonblock (O_NONBLOCK) Non-blocking open/read/write.
        cache (O_CACHE)       Attempt to keep data in file system cache.
        direct (O_DIRECTIO)   Direct disk access. (don't cache data).
        rsync (O_RSYNC)       Synchronize read operations.
        sync (O_SYNC)         Sync updates for data/file attributes.

    Output Open Flags:
        append (O_APPEND)     Append data to end of existing file.
        defer (O_DEFER)       Defer updates to file during writes.
        dsync (O_DSYNC)       Sync data to disk during write operations.
        trunc (O_TRUNC)       Truncate an exisiting file before writing.

    Delays (Values are seconds, unless microdelay enabled):
        cdelay=value     Delay before closing the file.    (Def: 0)
        edelay=value     Delay between multiple passes.    (Def: 0)
        rdelay=value     Delay before reading each record. (Def: 0)
        sdelay=value     Delay before starting the test.   (Def: 0)
        tdelay=value     Delay before child terminates.    (Def: 1)
        wdelay=value     Delay before writing each record. (Def: 0)

    Numeric Input:
        For options accepting numeric input, the string may contain any
        combination of the following characters:

        Special Characters:
            w = words (4 bytes)            q = quadwords (8 bytes)
            b = blocks (512 bytes)         k = kilobytes (1024 bytes)
            m = megabytes (1048576 bytes)  p = page size (8192 bytes)
            g = gigabytes (1073741824 bytes)
            t = terabytes (1099511627776 bytes)
            inf or INF = infinity (18446744073709551615 bytes)

        Arithmetic Characters:
            + = addition                   - = subtraction
            * or x = multiplcation         / = division
            % = remainder

        Bitwise Characters:
            ~ = complement of value       >> = shift bits right
           << = shift bits left            & = bitwise 'and' operation
            | = bitwise 'or' operation     ^ = bitwise exclusive 'or'

        The default base for numeric input is decimal, but you can override
        this default by specifying 0x or 0X for hexadecimal conversions, or
        a leading zero '0' for octal conversions.  NOTE: Evaluation is from
        right to left without precedence, and parenthesis are not permitted.

    Pattern String Input:
            \\ = Backslash   \a = Alert (bell)   \b = Backspace
            \f = Formfeed    \n = Newline        \r = Carriage Return
            \t = Tab         \v = Vertical Tab   \e or \E = Escape
            \ddd = Octal Value    \xdd or \Xdd = Hexadecimal Value

    Prefix Format Control:
            %d = The device name.          %D = The real device name.
            %h = The host name.            %H = The full host name.
            %p = The process ID.           %P = The parent PID.
            %u = The user name.

            Example: prefix="%u@%h (pid %p)"

    Time Input:
            d = days (86400 seconds),      h = hours (3600 seconds)
            m = minutes (60 seconds),      s = seconds (the default)

        Arithmetic characters are permitted, and implicit addition is
        performed on strings of the form '1d5h10m30s'.

    Trigger Types:
            br = Execute a bus reset.
            bdr = Execute a bus device reset.
            seek = Issue a seek to the failing lba.
            cmd:string = Execute command with these args:
              string dname op dsize offset position lba errno

            The first three options require Scu in your PATH.

        errors=1, files=0, passes=1, records=0, bs=512, log=stderr
        pattern=0x39c39c39, flow=xon_xoff, parity=none, speed=9600
        timeout=3 seconds, dispose=delete, align=0 (page aligned)
        aios=8, dlimit=64, oncerr=continue, volumes=0, vrecords=1
        iodir=forward, iomode=test, iotype=sequential

    --> Date: July 31st, 2004, Version: 15.10, Author: Robin T. Miller <--