From: Robert Klemme <shortcutter@...>
Date: 2008-06-28T21:02:38+09:00
Subject: Re: Big empty file creation

On 28.06.2008 12:23, Zhukov Pavel wrote:
> On Sat, Jun 28, 2008 at 1:22 PM, Robert Klemme
> <shortcutter@googlemail.com> wrote:
>> On 28.06.2008 11:10, ts wrote:
>>> Zhukov Pavel wrote:
>>>> I need to creat an empty file, over 10GB size.
>>>> Which way is fastest in file creation?
>>> use IO#sysseek followed which a IO#seekwrite
>> But note that this will not work on all OS in case the file must be
>> allocated.  Seeking likely creates a sparse file.
>>
>> Another approach is to use dd like
>>
>> dd if=/dev/zero of=your_file bs=1048576 count=10240
>>
>> That's probably as fast as it gets if you need blocks actually allocated to
>> the file.

> i can't use dd, cause i want a cross-platform application

dd runs on my Linux, cygwin, Solaris, HP UX... - pretty cross platform 
I'd say. :-)

The question is - do you need the whole file to be allocated or not?  If 
yes, a solution is slow regardless of programming language.

Cheers

	robert