The easiest way (and I believe the most reliable way) to do this is to first of all make sure all of your photo folders are within one master folder. Then, do the following:
1. Using your system browser, move that folder to the external hard drive.
2. Start Lightroom, where you will be notified that the photos are missing.
3. Right-click (Cmd-Click Mac) On the master folder and choose to update the folder location.
4. Browse to the new location of that master folder, choose it, and click OK.
A word of advice. If your photos and folders are not now organize within one master folder, don't just start moving them with your operating system. You'll need to organize them from within Lightroom.
Another way to move your folders to the external hard drive is to just drag/drop them in the tree view in the library module.
Jim, Thank you I will give this a try.
I have 50K + images on an external RAID drive of which one slice appears to have failed ( Disk Utility) Allimages are still accessible
LR 6 Mac OSX 10.10.4
I want to move all images onto a new external drive. Just to make sure I have it right before hosing anything would you mind clarifying a little.
In Finder create new folder (XYZ) on the RAID drive.
Drag & drop all folders into this new folder.
Copy the new XYZ folder to the new external drive.
'3. Right-click (Cmd-Click Mac) On the master folder and choose to update the folder location.' The master folder on the RAID drive?
'4. Browse to the new location of that master folder, choose it, and click OK.' The copied master folder on the new drive?
The only problem I can foresee is that we live in a rural area and have occasional power outages. It will take some hours to copy all these images & if there is an outage I presume that I would just have to start again?
The idea is that life is simpler when your photos reside in a directory tree that has only one top-level folder. One folder to move, one folder to "relocate" in Lightroom.
However, you don't need to create the XYZ folder if you don't want to.
If you currently have multiple top-level folders, you can move each individually then individually "relocate" each folder in Lightroom.
Since Lightroom does not currently know anything about folder XYZ, you will need to individually relocate each top-level folder any way.
Since interruptions are a possibility for you, you will want to do a COPY to the new drive(s) and not a MOVE. That way you have a backup on the original drive if something goes wrong during the transfer. After the COPY is successful, then you can delete the files from the original drive.