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How to create dummy 2G file

How to create dummy 2G file

How to create dummy 2G file

I would like to create a dummy file on a file system to verify that the file system can handle this size of a file.  I thought I could do this with the dd command using if=/dev/null of=/targetdirectory.
But I don't know how to tell it to put 2G of lovalues in the file.   I know there is a way - but maybe it is not using the dd command.  Anyone with an idea ?  I have already tried adding the dd options of count= and iblks=

RE: How to create dummy 2G file


you could write a Perl script to create a large file, something like this would do it.

#!/usr/bin/perl -w

my $buf = ' ' x (1024 * 1024);
my $i;

open(F,'>mybigfile') || die "can't open file\n$!\n";

  print F $buf;


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RE: How to create dummy 2G file

Don't need PERL to do that, simply use

dd if=/dev/zero of=/your/new/filename bs=1m count=4

First... when you read from /dev/null nothing goes out, but /dev/zero generates a continuous stream of zeroes. Give it a input and output block size of 1MB with bs=1m (you can use k to specify KiloBytes, and b to specify blocks).

I hope it works...

RE: How to create dummy 2G file

Thanks - the dd=/dev/zero .... worked fine.  

RE: How to create dummy 2G file

Hi guys
    there is a command in aix that creates a file with null characters its is lmktemp. the syntax is lmktemp filename size-of-file in bytes eg to create a 100 byte file called test. You type lmktemp test 100.

Let us know of the outcome.



RE: How to create dummy 2G file

The lmktemp worked fine - actually faster than the dd command.  Thanks.

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