Current Position:Home > Time Machine backup of LR on external

Time Machine backup of LR on external

Update:11-30Source: network consolidation
Does Time Machine automatic backups change how LR catalog backups can be handled?
I have original dng master files, lrcat file, and lrdata file on an external drive. It's a bus powered FW 800 that I keep with me between home and office. Both the home and office Macs have other externals used for Time Machine backups.
What's the risk of keeping lrcat backups (LR does one each time it opens) on external if Time Machine backs up hourly?
Thank you

The Best Answer

Ans to Q1 - only the lrcat file is backed up!
Ans to Q2 -The size of both depends on a number of factors, including: number of images in catalog, size and quality setting for previews (see attachment). The following examples are based on high quality Standard-sized Previews at 1680 pixels:
Example 1 - 2,560 raw images with full sized (1:1) previews built for each = 49.6MB lrcat file and 7.8GB lrdata file.
Example 2 - 22,400 raw images with only Standard-sized previews = 302MB lrcat file and 20.3GB lrdata file.
Example 3 - same files numbers as example 2, but 1:1 previews built for each - 302MB lrcat and 60.3GB
The following FAQ provides some insight on how the previews are stored and why dumping them doesn't always mean that they go away: