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[louissiscool]

Hey i recently started playing dwarf fortress and i am really enjoying the game.
But i have stumbled into a strange problem and all my save files have somehow become corrupted when i save the game manually anyone got any idea on how to fix the files or at least prevent this from happening again?

[PatrikLundell]

I don't actually have any advice since I haven't seen anything about such a problem, but those more knowledgeable than me will probably want to know what configuration you are using, such as DF version (if other than 0.40.24, which is the latest), utilities or packages, such as DFHack and Lazy Newb Pack, if DFHack is used, what utilities are enabled, any mods used, OS used, anything else that might be relevant.

[louissiscool]

Okay thanks for the reply, i am using the DF starter pack and i am using the phoebus graphic mod the game is the latest version i believe also my OS is windows 7.

[PatrikLundell]

Lazy Newb Pack's UI allows you to select whether to compress saves and whether to back them up. I assume these just reflect parameters in underlying text parameter files. Have you tried to play with these parameters? Compression in particular might be a corruption candidate.

[louissiscool]

i haven't played with any of the save game compression settings i read online somewhere that autosaves and normal saves sometimes cause this so i ahve started again with no auto save to see if it happens again.
Edit: After a quick check i noticed that save file compression was set to on i have turned it off will it come into affect straight away or will i need to start a new game?

[PatrikLundell]

You ought not have to start a new game, but I expect you'll have to exit and restart for it to be read anew.

[louissiscool]

well i will have to start again as when i loaded the game it stopped and said missing word definition any idea what that means?

[PatrikLundell]

No. My only guess is that I'm wrong and DF doesn't auto detect the save format, and thus requires the load and the save format to be the same (i.e. save compressed requires load compressed, etc.).

I'm a bit surprised none of the veterans have responded, but it might be a 4:th of July thing.

[Loci]

all my save files have somehow become corrupted when i save the game manually anyone got any idea on how to fix the files or at least prevent this from happening again?

Dwarf Fortress handles file i/o exceptions... poorly. If, for example, the disk becomes full the OS throws an exception, which Dwarf Fortress ignores and continues trying to write to the disk (unsuccessfully).

Common causes of corruption are full or nearly-full hard drives, hard-drive errors, and compression on a 64-bit processors. Theoretically, other programs reading or writing large amounts of data could also cause problems.

Corrupted saves generally cannot be repaired.

[Quietust]

Common causes of corruption are ... compression on a 64-bit processors.

Dwarf Fortress is a 32-bit application, and 64-bit processors are designed to perfectly execute all 32-bit code, so any compression error that occurs on 64-bit systems should be guaranteed to happen on 32-bit systems as well.

Theoretically, other programs reading or writing large amounts of data could also cause problems.

Theoretically, but extremely unlikely.

[Loci]

Common causes of corruption are ... compression on a 64-bit processors.

Dwarf Fortress is a 32-bit application, and 64-bit processors are designed to perfectly execute all 32-bit code, so any compression error that occurs on 64-bit systems should be guaranteed to happen on 32-bit systems as well.

Then you can explain why this is a frequently-reported bug on 64-bit processors?

[Quietust]

Common causes of corruption are ... compression on a 64-bit processors.

Dwarf Fortress is a 32-bit application, and 64-bit processors are designed to perfectly execute all 32-bit code, so any compression error that occurs on 64-bit systems should be guaranteed to happen on 32-bit systems as well.

Then you can explain why this is a frequently-reported bug on 64-bit processors?

It's probably because most people are running 64-bit systems nowadays, so a vast majority of compression-related bug reports are from said users. If there were problems with 32-bit programs running incorrectly on 64-bit systems, it would affect far more than just Dwarf Fortress, and you can bet that those problems would be very quickly fixed.

It's also worth pointing out that, prior to version 0.31.01, all savegames were compressed - the addition of COMPRESSED_SAVES only added a means of disabling it. If savegame corruption was a problem on 64-bit systems with 40d and earlier, I've certainly never encountered it...

[Eldin00]

While I have to agree with Quietust that the 64-bit CPU itself is almost certainly not to blame, I have run across occasional programs which exhibit bugs on 64-bit operating systems which don't occur on the equivalent 32-bit OS. Where I work we still keep a couple of 32-bit windows machines around specifically to cater to a small handful of 32-bit applications which work fine on Windows 7 32-bit, but have serious bugs on Windows 7 64-bit.

I can't say if the referenced bug in DF is such an issue, having never experienced it on either 32 or 64 bit systems.

[Quietust]

I should also point out that this comment claims that this sort of save corruption has also happened on Windows XP 32-bit, which further strengthens my comment above about 32-bit systems being significantly less common nowadays, especially among Dwarf Fortress users (who generally want >4GB of RAM anyways so that DF doesn't starve the rest of the system of memory), and thus being under-represented in bug reports.

[lethosor]

louissiscool: Could you upload your save file (say, to http://dffd.bay12games.com/)? I've seen "missing word definition" errors in a few reports of save corruption, but I'm skeptical that it's due to compression.

Edit: I put together a simple tool you can use to find compression issues in your save - run it in a command prompt with "df-savecheck <path to save>/world.sav" (or world.dat). It might be easiest to copy the df-savecheck executable into your DF folder and run a command prompt from there.