Modification dates change when moving/copying between hard-drive and flash

Question

Level 2

312 points

Modification dates change when moving/copying between hard-drive and flash

I use a flash drive to store most of my work-related documents on. That way, I have them when I'm at school (on a Windows XP computer) and at home on my Mac OS 10.3.9. I
try to occasionally back-up my flash drive by dragging it's contents to my Mac. Copying in this direction USUALLY retains the appropriate modification date.

However, if I move things from the Mac to the USB drive (I occasionally make changes to a file on the Mac when my flashdrive isn't handy), the modification date changes to the copy/move date. Is there a way around this? It alters the information about the file and sometimes makes a version look newer than another version of a document. When in reality, it’s older--it’s just been moved/copied and the date changed.

I often move things back and forth for backup purposes, but if it keeps changing the dates on it’s own, it’s impossible to tell which is REALLY the
most current copy/version.

Is there a fix so that copying and moving files between volumes does NOT change the modification date of the file?

Powerbook G4--12 in.--1.33 GHz Mac OS X (10.3.9)

Posted on Jul 29, 2006 9:44 AM

Reply

Answer 1

teacher24_70 Author

Level 2

312 points

Jul 30, 2006 10:52 PM in response to teacher24_70

No ideas on this? Doesn't this type of modification date change happen to others?

Reply

Answer 2

teacher24_70 Author

Level 2

312 points

Aug 12, 2006 6:53 PM in response to teacher24_70

Okay, since no one can explain WHY this happens, could someone at least try it on your end to confirm that's it's repeatable on someone else's system?

If you have a flashdrive, try copying a file from the flashdrive to the Mac--on mine, the modification date remains in tact.

However, if I move/copy a file from my Mac TO the flashdrive, the modification date changes to whatever date/time I moved it over.

Is there anyone that would be willing to try this for me so that I can see if it's JUST happening to me.

Powerbook G4--12 in.--1.33 GHz Mac OS X (10.3.9)

Reply

Answer 3

eww

Level 9

53,052 points

Aug 12, 2006 7:46 PM in response to teacher24_70

Hi, teacher. When my Lexar JumpDrive Secure is formatted as a MS-DOS volume so a PC can read it, the last-mod dates of files that I copy to it are changed to the date and time of copying. When it's formatted as a Mac OS Extended volume, the original last-mod dates are copied to it unchanged. Looks like you can thank Bill Gates for the inconvenience: apparently it's a DOS file system "feature". Don't you wish you could use Windoze all the time?

On second thought, the files really are changed when you write them to a DOS volume, because the DOS file system has no place to store the metadata about your files that a Mac pays attention to and a Windoze box doesn't. So when you write Mac files to a DOS volume, that metadata — which is part of each Mac file — is simply discarded, causing the last-mod date to change.

Message was edited by: eww

Reply

Answer 4

teacher24_70 Author

Level 2

312 points

Aug 12, 2006 8:20 PM in response to eww

So, if I want to have my flashdrive usable on BOTH my Mac and my work XP, then there's no getting my this lousy Windoze side-effect?

Thanks for the information. I had a feeling that it might have something to do with having to format it to be cross-compatible.

It just really throws a kink in the system when you're trying to see when a file was REALLY edited. Makes it SO much more difficult to see which version is the newest.

Thanks again.

Reply

Answer 5

eww

Level 9

53,052 points

Aug 12, 2006 8:42 PM in response to teacher24_70

Possible workaround #1: install Mediafour's MacDrive 6 on your work PC. That would enable it to read your flash drive formatted as a Mac OS Extended volume. Your file mod dates would probably still change when they were copied from the flash drive to the PC, but maybe that wouldn't be quite as confusing as what you're suffering now — you'll have to be the judge.

Possible workaround #2: code the actual mod date/time into your filenames.

Reply