You may consider keeping the catalog and the images on to a external hard drive.
You just need to connect the external hard drive to the computer you want to use. In this way, you will be able to use it on both computers without any issues.
Also, it will save the internal hard drive space of the computers as well.
Hope this helps.
The problem I have with this as a solution is that it adds to the complexity of backing up. Each "system" or device needs a minimum of 2 backups. So now I would need to backup:
Desktop x 2
Laptop x 2
Catalog/preview folder HD x 2
Hoping there may be another solution. Or maybe I need to find a better way to back up what is, after all, a small external HD?
Additionally, would I sacrifice speed by using an external HD? My desktop is a 2009 Mac Pro, which works great. Except it has slow inputs, USB 2, Firewire 800, e-sata. Realistically, I could use a flash thumb drive to hold the catalog and previews (SSD, fast), but as it would have to go through USB 2 on the desktop, I'm assuming it would bottleneck?
Just wondering if you came up with a solution to this?
I'm trying to do something similar and considering using a USB 3 128G flash drive (either as the primary catalog/previews folder for either desktop or laptop, or as a go-between that I sync with the primary folder on each machine before/after using LR)
Just noticed your post now after it was flagged as similar to the post I've just put up
Honestly, I haven't. So I'm sticking with using the laptop in Target Disk Mode. I'm able to add the laptop drive to Time Machine so I still have a multiple daily =backup, plus my regular weekly backups. It works so far....
I would use a small external 2.5" usb3 raid array. And then back that up to a cloud backup service. For me, cpu speed is the limiting factor, not the disk. That could be of course an issue if you import a lot of photos.