Excluding Items from Time Machine Backup

Exclude items from Time Machine backup

It is a good idea to exclude caches, temporary files, scratch volumes, etc from Time Machine backup. Excluding such items conserves space and reduces the time to backup.

Exclude items that can be regenerated, are transient in nature, or just don’t need backup.

How to exclude items

Open Time Machine system preferences, the click on Options… . The following dialog appears; you can drag things into it from the Finder.

I personally exclude system files and applications, because I backup those items via other means.

Excluding backup volumes

But a volume is used as a backup, then exclude backup volumes from Spotlight indexing (and also from Time Machine backup).

Exclude backup volumes from Time Machine; don’t backup a backup!

Adobe Lightroom considerations PERMALINK

The previews and cache generated by Adobe Lightroom should be excluded from backup, because they can be regenerated whenever desired.

Time Machine can and should be used to backup the Lightroom catalog file, but there are some caveats, see Adobe Lightroom and Time Machine Backup.

Especially with large 1:1 previews, the previews alone can total hundreds of gigabytes for users with many images. Previews are normally located in the same folder as your Lightroom Catalog, found in a folder ending in “...Previews.lrdata”.

Exclude Adobe Lightroom previews from Time Machine Backup

Apple Aperture considerations PERMALINK

The previews and cache generated by Apple Aperture are best excluded from backup, because they can be regenerated when desired.

Unlike Lightroom, Apple states that Time Machine can be used with Aperture without issues on Mac OS X Snow Leopard, but not Leopard.

Time Machine can and should be used to backup Aperture (in addition to other backups!).