Re: [Mldonkey-users] sparse file

[Lionel Bouton]

joseph wrote:

> if i understand correctly, if my mldonkey temp directory were on an 
> UFS partition, instead of an HFS+ partition (wich is the MacOS X 
> dafault, and i can confirm it doesn't support 'sparse files'), my 
> files being downloaded would only take the amount of space i actualy 
> obtained ? 


In fact the size of a chunk times the number of chunks from which you 
already downloaded something (mldonkey forcefully writes a whole 
zero-padded chunk on first downloaded byte from one given chunk, which 
triggers the allocation of the corresponding fs blocks). IE for ed2k : 
first byte downloaded -> 9MB allocated, no change until a byte from 
another chunk is downloaded then another 9MB block allocated and so on.

> if the above is true, what appends if i download the last chunk 
> (useful for preview)? would the temp file take the whole disk space of 
> the actual file ? 


No, on sparse-file supporting filesystem like UFS the allocation is done 
on a first write in filesystem block (the block's size depends on the 
fs, don't know for UFS, ext3 has support for 1k, 2k and 4k for example). 
Unless you write something, you don't allocate a single byte.

> so would it  be better to deactivate the 'download chunks in random 
> order' option in that case ? 


No need to do so. In fact this option only tells mldonkey what order it 
should favor, the actual download order depends of the chunks 
availabilities...

> sorry if this is obvious for you, but i'm a non-english and a non-unix 
> guy... 


I'm French too, but I'm definitely an unix guy :-)

> Jo.
LB