ruby Marshal serialization

Question

thanks for your time!

I get a class like this

class Vuser

    def initialize (logfile_name, iteration_hash)
        @logfile_name = logfile_name
        @iteration_hash = iteration_hash
    end

    attr_accessor :logfile_name, :iteration_hash

    def output_iteration_info ()
        puts @logfile_name
        puts @iteration_hash
    end
end

And there's will be an array to store the instance of Vuser Class. Let's say the array's name is vuser_ary.

I want to store this array ( vuser_ary ) to a binary file and I think it's called serialization. I google it and find Marshal in the standard library can do this. Here's an example how I do this according to the example on the Internet :

#serialization
File.open("some.file","wb") do |file|
   Marshal.dump(vuser_ary,file)
end

#loading
vuser_ary = nil
File.open("some.file","rb") {|f| vuser_ary = Marshal.load(f)}

But when I check the size of some.file. I find it's just four bytes. Then I realize that the data stored in some.file may be the reference but not the value of the vuser_ary.

Then my question is how do I store the value of vuser_ary to a binary file. How do I change my code to achieve that? Thanks in advance!

BTW: the value stored in vuser_ary will be like this :

RO_3.2_S4_CommericalRealEstate1_274.log