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[IanG]

Not for the first time, I've just had problems caused by my library getting corrupted.  Does anyone know how this can happen, and, more importantly, how it can be prevented?  

Could MC have some consistency checks and repair options built in?  Or, preferably, could the library be made more robust so that these corruptions don't happen in the first place?

Ian G.

 

[Will_L.]

Short answer - No. I've had corruption problems with the library since Media Jukebox 7. I have a little freeware app that copies the library to another location periodically for backup and that's my work around.

Just out of curiosity, how big is your library? Man's largish and I've always assumed that was the problem...

Will.

[Matt]

This shouldn't be happening.

Any steps to reproduce?  It's also possible you're having hardware memory failures.

[IanG]

Short answer - No. I've had corruption problems with the library since Media Jukebox 7. I have a little freeware app that copies the library to another location periodically for backup and that's my work around.

Just out of curiosity, how big is your library? Man's largish and I've always assumed that was the problem...

I've had the problem on 2 different PCs, neither of them has more than a few thousand items.  I use Cobian backup to make sure I've got a recent backup.

This shouldn't be happening.

Any steps to reproduce?  It's also possible you're having hardware memory failures.

No argument there  

Sorry, I've no idea how to reproduce the problem - the symptoms have been different each time, and have continued for a while before I've got desperate enough to replace the library.  I doubt it's memory problems - I've had trouble on 2 (or maybe 3?) systems, and I'm obviously not the only one.  And MC is the only app that's giving this sort of trouble.  

Ian G.

[JimH]

I don't think it's an MC thing.  Other possibilities are disk drive problems, memory errors, etc.

I had a similar weird problem a few days ago that was solved by uninstalling Norton AntiVirus.

Check the thread called "Weird and Wonderful" for other possibilities.  Omni's rigorous system check might be something to try.

[Jaguu]

some spyware detectors can also be very nasty!

[risingdamp]

Is it possible you are sharing the library with another pc running MC and both might be trying to write to the database at the same time?  

Could that back up program be trying to take a copy while MC is writing to the file?

Norton AntiVirus is a great product and I cannot believe that it would corrupt your MC library.  I've been using both for ages and never had any such problems.

Despite what JimH says, I wouldn't say that 'uninstalling an anti virus program' is a sensible way to solve a problem with your media library.  If Norton had interferred with it surely it would tell you so in the log.

[IanG]

Is it possible you are sharing the library with another pc running MC and both might be trying to write to the database at the same time?  

No. I just don't do that.

Could that back up program be trying to take a copy while MC is writing to the file?

It's possible, but I started doing the backups after I had a library corrupted.

Norton AntiVirus is a great product and I cannot believe that it would corrupt your MC library.  I've been using both for ages and never had any such problems.

Despite what JimH says, I wouldn't say that 'uninstalling an anti virus program' is a sensible way to solve a problem with your media library.  If Norton had interferred with it surely it would tell you so in the log.

I think it was Jim H who'd had the problem with Norton - I don't use it.  

Thanks for the suggestions!

Ian G.

[zxsix]

This doesn't apply to IanG, since he specified his library is not shared to other computers.  However, I know some MC users are doing this.  I thought I'd point out that in Windows XP and Windows 2000 Microsoft enabled a new feature called Opportunistic Locking.  This feature is not compatible with any multi-user database software!  It will cause corruption of the database if it is not disabled.
There is a registry edit that needs to be done to disable it.  If you run MC in a network environment, I suggest you go to Microsoft's Knowledge Base website and search on OPLOCKS.  You'll find the article that shows the registry edits to disable oplocks.

I work for a software company that produces a large multi-user database used by govt. and large private sector companies.  This OPLOCKS issue has our tech support staff working overtime.  Of course the calls always go, "all of a sudden we get db corruption errors several times a day, what's wrong with your program?".  This is of course a customer that's been running our software fine since 1998 and all of a sudden it's our problem   .  Turns out they installed new XP workstations and the trouble started then.  Disable oplocks on all workstations and server and no more corruption errors.   Since MC is technically a database, it would be affected similarly if more than 1 person could access the database over a network.

[JimH]

Thanks for that, zxsix.  I added it to the weird problems thread here:
http://yabb.jriver.com/interact/index.php?board=3;action=display;threadid=24031;start=msg170465#msg170465

We should dedicate that thread to all the people who do support.  

[KingSparta]

Thanks for that, zxsix.  I added it to the weird problems thread here:
http://yabb.jriver.com/interact/index.php?board=3;action=display;threadid=24031;start=msg170465#msg170465

We should dedicate that thread to all the people who do support.  

I think what would be better (or also) is that MC detect this condition and let the user know that this should be set to (what ever) and ask if you want MC to make this change for them.

Just as it did for auto incert a cd

I have no clue if My Computer is set up this way or not and i am sure other users don't also (I guess not since i don't have this problem).

[zxsix]

by default OPLOCKS is turned on.  You must go to the registry and manually change the setting from a 0 to a 1.
Keep in mind that you only care about this if you run MC over network file shares.  This won't affect the library server plugin in MC since that's read only and doesn't write back to the database (I think....if it updates the play count field in the database then it could be an issue).

My techs got tired of trying to get end user customers to get their IT staff involved to take care of this for them.  I ended up making a .reg file that my technical support staff could just email to them and tell them "double click this on all pc's running our software and you'll be set".  

[KingSparta]

I See

[raym]

by default OPLOCKS is turned on.  You must go to the registry and manually change the setting from a 0 to a 1.

According to Microsoft, the reg key to change is:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MRXSmb\Parameters\OplocksDisabled

...however this key doesn't even exist on my system (Win XP Pro SP2). I scanned the regisitry and it doesn't appear anywhere else either. I guess this is good news?

[KingSparta]

It may be on if the key is not there to turn it off

[zxsix]

If the key doesn't exist then it is enabled.
You need to create the key and set it to the disabled option.