Subject: Re: File > 2G on a dvd
To: Frederick Bruckman <fredb@immanent.net>
From: Wolfgang Solfrank <ws@tools.de>
List: current-users
Date: 11/29/2004 17:35:15
Hi,

>> Well, I once was thinking about support for this in NetBSD's cd9660, but
>> discovered that the there is no easy support for this, as the "file sections"
>> can be of arbitrary lengths, e.g. the first 3 sections could be 3 bytes each.
>> Which means that you cannot easily convert a file offset to a block number
>> and vice versa.  However, the fs independent code in NetBSD assumes in various
>> places that it _can_ do this conversion without the help of fs dependent code.
> 
> 
> I would think it would be much like appending a file, where the 
> subsequent bits may end up in a different cylinder group, but I don't 
> know my way around the file system code. [The level 3 file sections can 
> be anywhere on the disk, but they must be listed in order in the 
> directory, consecutively, and all but the first has the "multi-section" 
> bit set, all to make it practical for an implementation to assemble a 
> file from them, no doubt.]

No, this is not the same as files splitted to different cylinder groups,
as in that case, all parts are multiples of the block size.  I.e., in that
case the conversion of file offsets to relative block numbers in the file
is trivial.  See above about arbitrary lengths of the sections on ISO 9660.

Ciao,
Wolfgang
-- 
ws@TooLs.DE				Wolfgang Solfrank, TooLs GmbH