Editing on the CF Card

[kdaphoto]

I need an explanation about editnig on the CF card.  I know its not recommended but I did it.  Here's the sequence of events and what happened.

I inserted the card in to the reader then launched Photo Mechanic

I opened the folder, ranked the images I wanted, viewed only those images, copied those images to my hard drive

Quit PM then ejected the card.

Inserted a new card and launched PM.

When I opened the new card PM displayed thumbnails from the previous card.

I quit PM and looked at the card in Finder (Mac OSX, most recent updates), it was corrupt.  I couldn't open any files.  I used recovery software to recover the images.  They are safe and usable.

PM apparently copied the directory info from the previous card to the new card.

So given the sequence, why would the old directory still be held by PM and why is it applied to the new card?  Yes I will ingest cards first from now on but I just want to understand what happened.  Since I closed PM and ejected the card then reopened PM I assumed it would flush any old directory info.

Thanks.

[Kirk Baker]

I need an explanation about editnig on the CF card.  I know its not recommended but I did it.  Here's the sequence of events and what happened.

I inserted the card in to the reader then launched Photo Mechanic

I opened the folder, ranked the images I wanted, viewed only those images, copied those images to my hard drive

Quit PM then ejected the card.

Inserted a new card and launched PM.

When I opened the new card PM displayed thumbnails from the previous card.

I quit PM and looked at the card in Finder (Mac OSX, most recent updates), it was corrupt.  I couldn't open any files.  I used recovery software to recover the images.  They are safe and usable.

PM apparently copied the directory info from the previous card to the new card.

So given the sequence, why would the old directory still be held by PM and why is it applied to the new card?  Yes I will ingest cards first from now on but I just want to understand what happened.  Since I closed PM and ejected the card then reopened PM I assumed it would flush any old directory info.

Photo Mechanic does not cache directory information or files on disks.  The problem arises from an issue in Mac OS X where if a disk is not properly unmounted and a similar disk is inserted the Mac OS X's disk cache returns the contents of the previous volume.

This is a bug in Mac OS X and not an issue in Photo Mechanic.  I have told Apple about this issue a couple of years ago and it is still quite possible to reproduce the issue.  All one has to do is just eject the card from the reader without using the Finder and "soft-ejecting" the disc first.  Then if you put in a new card that has the same disk name (like NIKOND1) then Mac OS X doesn't think anything has happened and continues to provide the old information to all applications that read the filesystem.

It is up to the OS to flush filesystem information since it owns it.  Third party applications are not responsible for Apple's internal (private) disk cache.

I hope this helps explain things.

-Kirk