If the images on the second hard drive are in the same folder structure, All that is necessary is to go to the library module and right-click on a folder and choose to update the folder location. In the dialog that displays, point Lightroom to the folder on the second hard drive. If all of the folders are arranged within one master folder all you have to do is update the location of the master folder and all of the subfolders will update automatically. All of the adjustments that you have made will now apply to the images located on the second hard drive. Actually the adjustments will reference the images on the second hard drive. The images themselves will remain unchanged.
The second drive - with all the photos as backed up on import - has plenty of free space. I want my existing catalog to get the photos from that second drive so that Lightroom will be faster and less erratic.
Depending on the cause of Lightroom being slow and erratic, this change to use a different drive may have no impact at all.
Exactly what actions are slow in Lightroom? Exactly what is erratic? Please provide a lot of details.
Thanks - that was the kind of solution I was hoping was there, but just couldn't seem to get to it.
Thanks - I understand there are lots of other possible issues, but this one seemed obvious - I have a quarter million pictures in a catalog and the drive they are on has very little free space, so I either need to work from a different drive, or I need to free significant space on this drive. Then I'll see if I'm still having problems and if so, I'll look at the other possible problem areas.
Slowness in Lightroom usually doesn't depend on disk space available on the drive that holds the photos; it may depend on drive space available on the drive that holds the catalog or previews.
That is something to consider. How much free disk space is there on the drive containing your catalog and previews? I'm asking the original poster.
Jim and DJ are absolutely correct....
Also, how are the external drives connected to your computer with the LR catalog on it?
USB2 is really slow, Firewire 800 is also a bit slow, ESata seemed a bit faster, however, USB3 seems to work best...I personally have not tried Thunderbolt however I have read that is the fastest!
One other possibility on the drive containing your catalog and previews:
How do you have your previews set? Smart Previews and is LR working on those?
Or are they 1 to 1 previews and do you have LR keep the 1 to 1 previews indefinitely or are the large size previews deleted after say 30 days?
The large previews help when working on images, however they also take up space. It may be time for some "Spring Cleaning" of your catalog... Laura Shoe happens to have a free Spring Cleaning webinar this coming saturday at noon - it might also help! (no I do not work for her! just enjoy her teaching)
Photos on a USB2 drive would not cause noticeable slowness in Lightroom. Catalog on a USB2 drive would probably result in noticeable slowness.