I am running Lightroom 4 and keep all my photos on an external drive, (LaCie), backing them up to another external, (Big LaCie), but the lrdata and lrcat files are held on my start-up disk, (Mac SSD), for some reason and this is now so full that it is slowing up / stopping the whole computer.
(The Backups folder in the picture above simply holds backups of the data and cat files).
Obviously, I think, it would be best to move the data and cat files to the external disk LC but I am worried to do this and then find that these files will not be found by LR.
Please can someone tell me how I should resolve this issue while my computer still works? Cheers.
The catalogue file can be moved but if you're moving it to an external drive I'd add a word of caution.
It will almost certainly slow the running of LR down unless you've got a fast link external drive. There's noting to stop you copying it to the external drive as an experiment. I'd rename it whilst copying as you don't get confused as to which is which. You only need to copy the lrcat file. LR will rebuild the previews file.
Personally I'd look at other files that can be moved (starting with the LR backup files, as they shouldn't be on the same drive as your main catalog anyway in case that drive dies and you lose both the live catalog and all your backups...in case you're not backing up the backups somewhere else too). After that I'd move any files that are data/media from the SSD...Movies, Music Documents etc.
As for why the catalog is on your SSD, well that's where it will run fastest from (though differences vary from system to system). I have a separate SSD just for my LR catalog.