HD Homebrew Project Developement (Old Thread)

[sr.lucas]

There is something I do not get.
Why are we talking about partitions here? Every game has to create a new partition?
Isn´t only one PFS partition with all games in it?

(probably an stupid question)

[barf]

Are there any open source defrag tools around?

[romz]

There is something I do not get.
Why are we talking about partitions here? Every game has to create a new partition?
Isn´t only one PFS partition with all games in it?

(probably an stupid question)

Yes, I will create one or more partitions for each games, just like the HD loader does. There is no PFS driver in the CDVDMAN replacement, so it works with "RAW" partitions.

[_zaphod_]

Here is how fragmentation happens with hdl.
You instal two games, then delete the first one, you then install a smaller game. it goes before the second game, leaving a gap. As the process repeats, more and more gaps get put in as larger games are replaced with smaller ones.

A defragmenter can fix this, and juggle the patitions so as few are moved as eneeded to fill in the blocks.

A installer can also make an effort to use the fragments when they exist, to make future installation smoother.

[rainrix]

Defragmenter is useless, i've never had any problem of slowing or anything on my 80 Gb hard drive and the games turn over is hight on my disk. I guess fragmentation happen to be a probleme when the files are small and several. In our case the parts are so big that it doesn't make problem.

[cmal1492]

sr.lucas: HDLoader uses a partition with all/RAW data from the CD/DVD written into it, and it mounts it and pretends it is a CD/DVD - if it just copied the files into a PFS partition then many games wouldnt work as they rely on LBA and similar methods to find files on the disk; LBA would not work the same if the files from the disk were simply in a PFS partition... its also why some games are "shrinkable" before you put them on the PS2 HDD (fake LBA that says there is more data than there actually is).

rainrix: I have seen install times and load times mariginally decrease due to defragmenting - at the same time, 3/5 times using the official sce defrag I have had a corrupt hard disk as a result when partitions are present that dont come from sce or HDL.

[barf]

Defragmenter is useless, i've never had any problem of slowing or anything on my 80 Gb hard drive and the games turn over is hight on my disk. I guess fragmentation happen to be a probleme when the files are small and several. In our case the parts are so big that it doesn't make problem.

I do not want to defragment the files,
but the location of sub partitions.

If all sub partitions are of a static size,
fragmentation will not occur, and optimalization of location will become easier.

Just philosophy level what I am doing but, let's say we would like to install a game it would always be fragments of a static size, when a game is deleted the new games installed should be able to use the empty sub partitions.

[dlanor]

I do not want to defragment the files,
but the location of sub partitions.

And that is exactly what we've been discussing too.

If all sub partitions are of a static size, fragmentation will not occur, and optimalization of location will become easier.

That is not correct. If it had been, then all fragmentation would just be a result of choosing non-static sizes, which is definitely NOT the case. Fragmentation can and will occur whenever the total size of a data unit (here an entire game ISO) exceeds the minimum storage fragment size, and such data units may be alternately added and removed from storage.

In order to make your statement true, the minimum storage fragment would have to be equal to or larger than the maximum data unit, in our case appx 8.5 GByte. That size would then have to be used by all ISOs, even those who could have been stored in much smaller fragments. Such waste is not acceptable.

Just philosophy level what I am doing but, let's say we would like to install a game it would always be fragments of a static size, when a game is deleted the new games installed should be able to use the empty sub partitions.

They should be able to do that in any case, but that does NOT mean that fragmentation is eliminated. Eliminating fragmentation would mean that each data unit was stored as one contiguous block, which is not possible without constant defragmentation operations.

However, if the negative effects of fragmentation (mainly access delays) can be kept to a minimum, then there is no real need to defragment at all. For example, with a fragment size of 128MB (our current minimum) we will suffer an extra delay corresponding to repositioning disk access heads only once per 128MB, which we are not likely ever to notice.

The only aspect of fragment size which could warrant raising the minimum size slightly, from 128MB to 256MB is that 65 partition limit per ISO romz mentioned.

With a minimum subpartition size of 256MB we would always be certain of being able to store a full DVD-9 ISO, as long as the total free space was sufficient.

Best regards: dlanor

[_zaphod_]

Yeah that's probabl y the best bvit. with a min partition size of 256, it' simpossible to run out of space for a dvd-9 de to fragmentation, no matter how big the turnover.

[TnA]

Any news? ?(

Hm,... When I come home, I definetly must try to set up my SDK and to get my DSL-Flatrate.