Excluding Lightroom Previews and Smart Previews From Your Backblaze Backup
March 17, 2015
6 comment
Turns out, this post appears unnecessary. Since the preview files can be regenerated, Backblaze saves bandwidth and doesn’t bother backing them up. See: Does Backblaze backup my .lrdata files in Lightroom?


I was asked an question by Matt on Twitter about backing up my Lightroom Smart Previews with Backblaze. Matt tweeted:

Nice mobile wkflw. How do you exclude Smart Previews from backing up to Backblaze? Aren’t’ SP baked into respective catalogs?

Where I think Matt was going with his question was that the Smart Preview file can get pretty big and, especially with the initial backup, can slow down the entire backup process. Excluding the Smart Preview file from the backup could help get that initial backup done and make subsequent backups more streamlined, especially since those files can change often.

Personally, I include the Smart Preview and Preview files in my Backblaze backup because I have unlimited storage and a fast internet connection. But the data in both of these files is very transitory. The most important files to back up are the ones that can’t be recreated and, for Lightroom, that’s your catalog file along with your original image files. The other files, including the Preview and Smart Preview file, can be recreated if you have a good catalog and the original images, so backing them up is not as critical as the catalog file. If you are working with a slower connection or do have storage constraints, excluding the preview files from your backup might be a good option.

Currently, Backblaze doesn’t provide a way to pick specific files to exclude from the backup, but you can exclude files of a certain type. Lightroom uses the .lrcat extension for the catalog, and a .lrdat extension for both the Preview and Smart Preview files, which means you simply need to add “lrdat” to the Blackblaze exclusion screen.

Open up your Backblaze preferences screen and navigate to the Exclusions tab. Find the file types box at the bottom of the dialog screen and add “,lrdat” to the list. Backblaze will no longer back up any files that end with .lrdat, which means both the Previews and Smart Previews, but it will still back up your catalog file, since that ends in .lrcat.

backblaze lightroom catalog smart preview exclusion lrcat lrdat

Lightroom Fanatic > Backblaze Exclusions

Thanks for the question, Matt. I hope thhis helps. Remember, if you have a question for me, reach out to me on Twitter at @lrfanatic!


I use Backblaze to keep my computer and attached storage automatically backed up. It’s nonintrusive, fast, secure, and starting at only $5/month, it’s a no-brainer. Rest easy knowing that your files are backed up by signing up for BlackBlaze today.

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There are 6 comments

  • bill says:

    i have no exclusion rules for lrdata, but i can’t see it in backblaze ?
    any idea ?
    the same for xmp write next to raw files…

    I can’t see thoses files in restore view in backblaze.
    And you ?

    thank you.

    • dave says:

      Hi, Bill. I can see both the .lrcat and XMP files using the Backblack web interface.

      Do you see your raw files?

      A few things you might be able to try:
      1. Reconfirm that you aren’t excluding those file types or folders from your backup.
      2. Confirm that the folder where your images and catalog files are included in the backup.
      3. Make sure backblaze is backing up…if you newly installed it, maybe it’s not done backup up yet.
      4. Make sure the lrcat file isn’t larger than your “max file size” setting (I know this wouldn’t impact the XMP file).

      Otherwise, you may need to open up a Backblaze support ticket.

  • bill says:

    Maybe i’ll open a ticket, because i have backblaze for few years now, and backup is finished…
    here are my setup and folders.

    thank you, and thank for your nice blog 😉

  • bill says:

    i contact support and so yes, as you notice in your post update, lrdata are not backed up, it’s normal, as it’s said in support.

    For xmp, it was just my fault, i had a xmp extension in ignore list a long time ago, i forgot to remove !