From: Eleanor McHugh <eleanor@...>
Date: 2008-06-28T20:39:04+09:00
Subject: Re: Big empty file creation

On 28 Jun 2008, at 09:57, Zhukov Pavel wrote:
> I need to creat an empty file, over 10GB size.
> Which way is fastest in file creation?
>
> ------
> file<<"0"*file_size_in_bytes
> -------
> consme too much memory
>
> -------
> for i in 1...x
>  file<"0"file_size/x
> end
> -------
> too slow :(


Pick a value of x that's a multiple of 512 bytes as this will match  
your data writes to the OS's disk cache. This may or may not gain you  
some performance advantage which will vary depending on the underlying  
cluster size of the file system, general filesystem overhead, disk  
fragmentation and a host of other properties that our outside your  
control as a programmer. Even coding is assembler creating a 10GB file  
with each byte zeroed is going to be a slow process...


Ellie

Eleanor McHugh
Games With Brains
http://slides.games-with-brains.net
----
raise ArgumentError unless @reality.responds_to? :reason