Issue with External Image Drive

[asislen]

   
    I'm hoping someone will be able to help be solve a problem I'm having. I'm running LR CC 2015.7 and Mac OS X 10.11.6. I keep my images on an external 8tb HGST drive that is in a dock and have no problems or issues. I recently bought an external 8tb G-Technology RAID, that is set for RAID 0. I want to use this drive as an exact duplicate of my 8tb HGST drive for all my images when I teach outside of my studio.  I want to be able to make the 8tb G-Technology RAID my "traveling" image drive, i.e. in essence, a duplicate of my 8tb HGST "home" image drive.

    Here's the issue. I copied my entire 8tb HGST drive over to the 8tb G-Technology RAID. So far, so good. So the LR catalog would be happy with either (not both) drive attached to my computer, using the Finder, with the 8tb HGST drive ejected, I gave the G-Technology RAID the same "name" as my 8tb HGST drive. With only the G-Technology 8tb RAID attached, Lightroom recognizes all the images (no "!'s" or grayed out file folders). Everything seems to work perfectly with one exception. If I right-click on any file folder in the Folders left panel, and choose Synchronize Folder, the Synchronize dialogue box opens and it says it needs to Import every image in the folder as a new image, and that it will Remove the same number of missing photos from the catalog. 

    I have ejected the 8tb G-Technology RAID and plugged the external 8tb HGST drive back in. If I right-click on any folder and select Synchronize Folder, it comes back with 0 files needed to be synchronized. So somehow the issue is with my 8tb G-Technology RAID, even though in the Finder, when only that drive is plugged in, it shows with the exact same name as my 8tb HGST drive.

    If both my drives have the exact same name and only one is plugged in at a time and if both drives contain exactly the same images, and if there are no "!'s" or grayed out folders with "?'s" with either drive, then why does LR think it needs to do a Synchronize the folders on my 8tb G-Technology RAID?

    Any help or suggestions would be GREATLY appreciated!
     

[schertz]

Speculation inbound....
I'm not sure that anyone outside of Adobe could tell you definitively how exactly LR determines the identity of a file. It might be something as simple as the path and filename, or something more complex like including the creation/modification date or even the inode value of the data. The code that determines if a ! appears might be more simple (just path and filename) while the code that looks for new files to Sync/import might look at the ? inode values. You could test that by making a hard link to an image file and see how lightroom treats it (I'm not necessarily endorsing trying that...) EDIT: Nevermind, I just tested it and two file names with the same inode value both import separately when you sync a folder.

As a solution, you could just use the one volume for work and travel, and leave the other as a backup drive that stays home. You can just do a clone backup when you get back home. I'm not sure I see the value trying to maintain to separate (identical) data sources with one catalog.

MS

[Wayne Fox]

The logic is sound but the drives are identified by the Mac OS by more than just the name of the drive, which may be causing some issues.

I have a couple of suggestions.  First, put everything inside a folder on each drive, the folders will have the same name but the drives are named differently (for your convenience.)  Then when you use Lightroom, all you need to do is right click on that top level folder and "locate it", and everything will flow down down correctly throughout your file structure.

Second, rather than use the finder to copy your drive over, I would use Carbon Copy Cloner.  You can create two tasks, one to copy the main drive to the traveling drive, then one to clone the traveling drive back to the main drive. This will insure both drives are an exact copy.

[asislen]

Wayne,
Thanks VERY much for your comments.  I'll definitely give it a try!  Actually, I didn't use the "copy" command to copy all the files.  I've been using ChronoSync with verification "on" which I understand is very similar to CarbonCopy.
Thanks again.
Alan

[fdisilvestro]

Another option you might consider is to use smart previews, which could be stored in the internal drive. You can perform edits with them and the adjustments will be applied to the original images as soon as they are connected.

The only limination I see is that you cannot zoom to 100% as the smart previews have a fixed size and you cannot export final images.

Just a note: If you use 1:1 previews (in addition to the smart previews) you will be able to zoom 100% in the library module.