Here is the scenario;

a) While testing the Memory Unit handling on a game, I pulled the MU out immediately after selecting it from the Storage Guide.
b) The game threw an exception (probably OpenContainer) and so I noted it.
c) I ran the game a second time, once again selecting the MU but this time NOT removing it.
d) When the game accessed the MU, it threw an exception.  At this point I had figured my first removal had corrupted the file.
e) I went to the Dashboard and removed the entire XNA folder from the MU to be sure I got all the save files related to the game.
f) I repeated step (c) and got another exception.  Same results.  Now I'm thinking it's a coding error.
g) I repeat step (c) but this time I select HD instead.  The game did NOT throw an exception.  Now I'm back to thinking it's the file.
h) I return to the Dashboard and FORMAT the MU
i) I run the game a final time, select MU from the Guide... and access to the MU was successful.  The game did not throw an exception.

Is it possible that a corrupted file small enough can be left on a Storage Device as to not be visible by the Dashboard?
This is not the first time I've seen a situation where a game has thrown a mysterious exception while accessing Storage when all the game files have been "visibly" removed.

-Dave

Silver Dollar Games 1:

Is it possible that a corrupted file small enough can be left on a Storage Device as to not be visible by the Dashboard?

I seriously doubt this is possible.  Even knowing very little about low-level file systems, this is a fundamental thing.  And were it broken, it would be showing up all over the place (especially with millions of 360s out there).

Dark Flow Studios:

And were it broken, it would be showing up all over the place (especially with millions of 360s out there).

Probably because the only people that select a MU and then pull it out at the same time are the XNA Creators club members! One of my reviewers experienced the exact same problem.

SniperED007:

Probably because the only people that select a MU and then pull it out at the same time are the XNA Creators club members! One of my reviewers experienced the exact same problem.

So what you're saying is that you do think it's a problem with the low-level file system?  And not Silver Dollar's code?  And not your code?

It's difficult to say, I personally cannot recreate the problem so I cannot debug it to tell you on what line or why it was crashing in that case. All I know is that with a corrupt save game it doesn't crash so it must be something else.
I just don't think it's healthy to remove a MU out whilst selecting/saving to it.

SniperED007:

I just don't think it's healthy to remove a MU out whilst selecting/saving to it.

lol  It's most definitely not a good idea to do that, especially regularly.  However, with that being said, it's something that even the big boys releasing AAA retail games have to be able to handle.  Every one of those types of games goes through an extremely thorough certification process.  All of the games out there on the shelf today passed the "pull the MU while saving" test.  So odds are, this is probably a problem with your code, or possibly (although remote) a problem with the XNA low-level code.  Tough to say though.  Repro cases are always your friend in these types of situations. :)

Well in my case I decided to wrap my entire save section in a try catch, just in case of any crazy issue like that. Haven't had anyone report any issue since then.

Silver Dollar Games 1:

Is it possible that a corrupted file small enough can be left on a Storage Device as to not be visible by the Dashboard?

As others have stated, that is not very likely. Pulling the MU while it is being accessed can easily corrupt the filesystem on it. That is why formatting it, fixed the issue. Whenever I read about someone testing this, I cringe. They should be prepared to lose everything on the MU.

Is this actually something that needs to be tested? I feel like pulling out a memory unit right when it's being selected passes over from "Trying to break the game" into "Trying to break your hardware." What's next - requiring testers to kick their XBox 360 periodically during testing? Implementing a 5 foot drop-the-XBox test?

Dark Flow Studios:

All of the games out there on the shelf today passed the "pull the MU while saving" test.

How do you know this? I couldn't find any information from a few quick Bing searches, and the Xbox TCR is (IIRC) under an NDA.

SniperED007:

Well in my case I decided to wrap my entire save section in a try catch, just in case of any crazy issue like that. Haven't had anyone report any issue since then.

Yep, this is what I always do.

RainbowDespair:

Is this actually something that needs to be tested? I feel like pulling out a memory unit right when it's being selected passes over from "Trying to break the game" into "Trying to break your hardware." What's next - requiring testers to kick their XBox 360 periodically during testing? Implementing a 5 foot drop-the-XBox test?

IMHO, if the user pulls out a MU during a load or save operation, they deserve whatever bad things happen. ;) However wrapping your save/load operations like above should be all that's necessary to make sure nothing happens.

And yes, testing this is problematic for some. I store my profiles and game saves on my MU, so I'm obviously not going to be doing it! I may have to get another MU now, just to test this.

UberGeekGames:

IMHO, if the user pulls out a MU during a load or save operation, they deserve whatever bad things happen. ;)

IAWTP!

UberGeekGames:

Dark Flow Studios:

All of the games out there on the shelf today passed the "pull the MU while saving" test.

How do you know this? I couldn't find any information from a few quick Bing searches, and the Xbox TCR is (IIRC) under an NDA.

I don't know about disk releases, but the TCRs for XBLA don't mention pulling the MU out (only that MU support is required). Then again, the XBLA TCRs inherit from the regular TCRs, which I've never seen, so... *shrug*

BShields:

I don't know about disk releases, but the TCRs for XBLA don't mention pulling the MU out (only that MU support is required). Then again, the XBLA TCRs inherit from the regular TCRs, which I've never seen, so... *shrug*

Jim Perry:

UberGeekGames:

IMHO, if the user pulls out a MU during a load or save operation, they deserve whatever bad things happen. ;)

IAWTP!

People seem to forget that this is entirely possible to do by accident with games that save data frequently.  Also, a person that is very eager to shut down the XBox and take his MU with him (to get home in time for supper, etc.), may inadvertantly yank it a little bit too soon before the save was finished.

WolRon:

People seem to forget that this is entirely possible to do by accident with games that save data frequently. 

It should never happen if the game does the right thing and tells the player that it's saving.

Most retail games will warn you not to shut off the console/remove storage while saving, usually with some sort of icon displaying such an event.  Considering the length of time it takes to save a large game (Oblivion or Fallout, for example), with the possibility of corrupting the file, I think warning the user is the best thing we can do.

Dark Flow Studios:

BShields:

I don't know about disk releases, but the TCRs for XBLA don't mention pulling the MU out (only that MU support is required). Then again, the XBLA TCRs inherit from the regular TCRs, which I've never seen, so... *shrug*

Yes, but don't both sets of TCRs require the game to gracefully handle corrupt save games and any other corrupt data associated with the game?  I'm pretty sure they do.  Therefore, by proxy, they must be able to handle the case of data that is corrupt because somebody decided to pull the MU while the game was saving.

IIRC, the XBLA TCRs say nothing about corrupt file handling, only that MUs *must* be supported, since the HD may not be available. However, again, the XBLA TCRs inherit many rules from the normal TCRs, which I've never seen.

I can say that for DVD games you are required to show the saving - do not turn off etc. message on the Xbox whenever saving. The PS3 has an even longer message you must display. It has been a while, but I don't remember anything about pulling out Memory Units. Heck most DVD games don't even handle taking the DVD out while the game is running.

Patrick

I personally think pulling out the MU is a good test...

Has nobody here ever owned a electronic device in which the contacts where a bit dodgy, (mobile phone batteries can be especially bad for this). If an MU is faulty and happens to somehow lose its connection by any other means such as a loose connector. Then pulling out the MU also tests how a game will deal with this situtation and not necessarily purely for the sake of someone who rips out the MU on purpose during the save process.

It's a pretty nice safe guard against this kind of thing.