Ext4 - File pre-allocation?

[Ux64]

Does Deluge use file pre-allocation when using full allocation on ext4 file system? Does Deluge Windows version use pre-allocation because NTFS supports it too?

- Thanks

[andar]

Currently, Deluge only uses sparse-files for it's "full" allocation.

[k3rnelmust4rd]

Is this still true? Also, are there any known issues with this? I'm using an ext4 partition, and I don't think it's pre-allocating at all. Eventually I'll get an out of space error on one or several torrents, and if they were pre-allocating that shouldn't happen (because it should have allocated all the space it needs already).

I'm using latest deluge in apt for Linux Mint 9 (which is what I'm using).

[Ux64]

Currently, Deluge only uses sparse-files for it's "full" allocation.

Hmm, I don't have a clue how ext4 works with sparce pre-allocated files. Does it pack data in compact set, causing fragmentation. Or does it spread out data as it should(?) to prevent frangmentation. Of course it's quite impossible to create sparse file without pre-alloacation. So I assume both features are used together.

Sparse allocation would work just fine with this spread out approach. Only difference to traditional non sparce solution would be that cluster in between are usable.

File:

FFFFFFFF (Free disk space)

Blocks being allocated with torrent download, out of order as usual. But what method is used to write the data to disk?

1. 1FF4FF7F or

2. 147FFFFF ...

I personally think that it must be 1. because otherwise it woudln't make much sense.

Does anyone know real and confirmed to be true answer for this? Because with later approach now when blocks 2,5,6,8 come in file is already fragmented.

At least 7-zip nicely fails with this, making lots of fragmentation when ever handling files. It's not using sparce files, but it only fails to use pre-allocation. Which is major fail I think.

Does anyone know how sparse files work with NTFS when allocating space?

- Thanks!

Full allocation (just writing large file at once), sparce files (allowing unallocated gaps in file) and pre-allocation (acquiring disk space at once without writing to it) are completely separate things. Full allocation doesn't have anything to do with pre-allocation, pre-allocation is file system feature. But pre-allocation can be used to achieve full allocation easily and quickly.
keyword Preallocation

[k3rnelmust4rd]

So, I'm not sure how sparse files work in general, but it doesn't seem like they're doing anything at all. Both 'df -h' and 'ls -sh' seem to say that the file is only taking up space is it needs it...