HOWTO: Create a file exactly x in size

[Leon Smith]

Does anyone know of a simple command create a file exactly a given size.

i.e I want to create a file exactly 1MB in size. This will be used to fillup filesystems for testing.

Similar to SUN's mkfile command used for creating swap space.

Thanks in advance.

[Patrick Wallek · Accepted solution]

Have a look at the 'prealloc' command. I don't remember the exact syntax (that's why they make man pages), but that is the command that you want.

[Patrick Wallek]

OK, I found the man pages on HP's docs site:

To create a file called myfile that is 1MB in size:

prealloc myfile 1048576

The size is specified in BYTES.