I needed such files to test a networkshare.
I wanted to know how fast I could move files there in different sizes and counts.
All we need in this case is an *NIX box and dd.
Corresponding to dds man page which is:
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DD(1) User Commands DD(1) NAME dd - convert and copy a file SYNOPSIS dd [OPERAND]... dd OPTION DESCRIPTION Copy a file, converting and formatting according to the operands. bs=BYTES read and write BYTES bytes at a time (also see ibs=,obs=) cbs=BYTES convert BYTES bytes at a time conv=CONVS convert the file as per the comma separated symbol list count=BLOCKS copy only BLOCKS input blocks ibs=BYTES read BYTES bytes at a time (default: 512) if=FILE read from FILE instead of stdin iflag=FLAGS read as per the comma separated symbol list obs=BYTES write BYTES bytes at a time (default: 512) of=FILE write to FILE instead of stdout oflag=FLAGS write as per the comma separated symbol list seek=BLOCKS skip BLOCKS obs-sized blocks at start of output skip=BLOCKS skip BLOCKS ibs-sized blocks at start of input status=noxfer suppress transfer statistics BLOCKS and BYTES may be followed by the following multiplicative suffixes: c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y. Each CONV symbol may be: ascii from EBCDIC to ASCII ebcdic from ASCII to EBCDIC ibm from ASCII to alternate EBCDIC block pad newline-terminated records with spaces to cbs-size unblock replace trailing spaces in cbs-size records with newline lcase change upper case to lower case nocreat do not create the output file excl fail if the output file already exists notrunc do not truncate the output file ucase change lower case to upper case swab swap every pair of input bytes noerror continue after read errors sync pad every input block with NULs to ibs-size; when used with block or unblock, pad with spaces rather than NULs fdatasync physically write output file data before finishing fsync likewise, but also write metadata Each FLAG symbol may be: append append mode (makes sense only for output; conv=notrunc suggested) direct use direct I/O for data directory fail unless a directory dsync use synchronized I/O for data sync likewise, but also for metadata fullblock accumulate full blocks of input (iflag only) nonblock use non-blocking I/O noatime do not update access time noctty do not assign controlling terminal from file nofollow do not follow symlinks Sending a USR1 signal to a running `dd' process makes it print I/O statistics to standard error and then resume copying. $ dd if=/dev/zero of=/dev/null& pid=$! $ kill -USR1 $pid; sleep 1; kill $pid 18335302+0 records in 18335302+0 records out 9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s Options are: --help display this help and exit --version output version information and exit AUTHOR Written by Paul Rubin, David MacKenzie, and Stuart Kemp. REPORTING BUGS Report dd bugs to email@example.com GNU coreutils home page: <http://www.gnu.org/software/coreutils/> General help using GNU software: <http://www.gnu.org/gethelp/> COPYRIGHT Copyright © 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>. This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. SEE ALSO The full documentation for dd is maintained as a Texinfo manual. If the info and dd programs are properly installed at your site, the command info coreutils 'dd invocation' should give you access to the complete manual. GNU coreutils 7.4 March 2010 DD(1)
So next we need something to fill our file with. While in *NIX if you want to move something into a deep ground of nothing you will use /dev/null. Everything get lost in there. On the otherhand you have /dev/zero which is basically the same but when you read from it you get as many zero charakters as bytes requested.
So let's do this thing!!
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dd if=/dev/zero of=testfile count=1024 bs=1024
The line above will create file called testfile with an 1MB filesize. But how?
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if=/dev/zero # defines the in file of=testfile # defines the outfile count=1024 # read only 1024 blocks at once bs=1024 # at least define the size of the new file
which is 1024*1024. AS there the size of the new file is 1Mb. To get an file with 1Gb use 1024*1024 which is 1048576.
I hope this helped.