One of the biggest challenges in using Lightroom is the question of how to use it across multiple computers and keep everything in sync. There aren’t a lot of very good solutions out there (most with significant downsides) and even fewer how-to guides. In today’s post we’ll introduce one possible approach and walk you through how to implement it.

The external drive solution

The simplest solution - and the one we settled upon - is to simply move the entire catalogue and files to an external drive, and then use this as the single canonical catalogue for the version of Lightroom that existed on each computer.
 Like with all things, there are both positives and negatives to consider when implementing this approach.

The Positives

  1. It’s dead simple. With a single hard drive there’s no “sync” involved because each computer is automatically updating the same catalogue and files
  2. It frees up lots of space. Especially on a laptop, even just a few mid-to-large sized photoshoots can easily chew up hundreds of gigabytes of hard drive space. Moving everything to an external disc frees up this space.

The Negatives

  1. It’s risky. Not only are all your images and catalogue in a single point of failure, it’s a portable hard drive. Bouncing and being shuffled around, it’s a much higher risk of being lost, stolen or failing than something sitting safely in your bedroom. A good backup strategy is an absolute must - see below for our solution.
  2. It can be expensive, if you go high end. While your basic portable HDD is pretty dirt cheap, as downside #1 above makes clear, you’ll probably want to be investing in quality hardware - this means a fast USB 3.0/C or Thunderbolt connection, and if you can, an SSD to avoid the downside of moving parts that can break when being carried around outside. This can get very pricy, very quickly, especially once capacities start creeping north of 500GB.
  3. It’s yet another thing to carry around & plug in. Not only do you have to always remember to bring your hard drive with you if you’re planning on doing any image work - you also need to deal with it dangling off of your laptop, taking up ports and so forth - especially an issue with single port devices like the 12” Macbook, for example.

Assuming the upside above are sufficiently enticing, and the downsides are things you an live with, then the next question is - assuming you’ve been working on Lightroom on a single computer up until now - how do you move your files and catalogue to the external drive?

Moving your files to an external drive

For the rest of this post, we’ll be referring to three main entities:

  1. external drive: Assumed to be the portable hard drive that will house your canonical Lightroom Catalogue and source images
  2. primary computer: For convenience sake, refers the computer you’ve been using Lightroom with until now. In general, we assume it to be the less-portable computer which remains at your home, but it needn’t be used at your home, and it doesn’t need to be a desktop.
  3. secondary computer: For convenience sake, refers to the second computer you will be using Lightroom with.

With that nomenclature in mind, the process to move the files to an external drive are as follows:

  1. First, put a dummy RAW file in your external drive, connect it to your primary computer and then import the RAW file in place within Lightroom so that the external drive will show up in your Folders sidebar
  2. Next, select all the folders in your primary computer Lightroom catalogue and drag them to the external drive within the Lightroom interface. It is important you do this within Lightroom and not your file manager!
  3. This process is likely to take a while and unless you have very fast equipment (i.e. SSD drives on both ends and a Thunderbolt or USB 3.0+ connect on both ends) you may be better off to move one folder at a time.* With fast equipment, you can probably drag and drop everything at once, but just make sure to leave it alone for the entire time (easily hours, depending on how much data you need to move) it’s doing it’s thing. The last thing you want is to interrupt Lightroom in the middle of this process.**
  4. After this is done, click “Lightroom” → “Catalogue Settings” → “Show Catalogue”. This will open the folder containing your Lightroom catalogue.
  5. Completely exit Lightroom - then, physically move the entire contents of the catalogue to the external drive.
  6. The next time you restart Lightroom, you will be asked to choose a Catalogue (or if not, you can do so manually from the File menu. Choose your new catalogue and you should see all your files running off the external disk.

* Lightroom is very naive in how it handles file management and if you drag 40 folders with hundreds of images in each, it will try to move all the folders at once basically leaving you with 40 folders all filling up 1 or 2 images at a time, tons of disk thrashing and a disastrous mess if (heaven forbid) your move gets interrupted.

** In the unlucky chance that Lightroom crashes or otherwise gets interrupted in the middle of this move, you are going to be faced with the very unpleasant situation of having your photos strewn across both your primary computer and external drive. In this case, the safest thing to do is to restart Lightroom, and again, from within the Lightroom interface, painstakingly and manually move the files from inside each folder within your primary computer to the external drive - you won’t be able to drag the entire folder itself in one go anymore because Lightroom will complain it already exists on the external drive and it has no concept of “merging.” Do this one folder at a time and if you get an error (usually something like “XXXX file could not be moved because the source file cannot be found”) manually confirm that each file in question actually physically exists in the external drive folder (via the Finder) before deleting it from the corresponding folder in the primary computer.
 Whatever you do, do not be tempted to use the file manager to delete all the files on the external drive and then start over again - those files on the external drive really are on there and have been deleted from your primary computer. Similarly do not attempt to use the file manager to physically complete the move - use it only to confirm that files that LR gives an error for really do exist on the destination drive before deleting them from source.

If you don’t follow these instructions, you are likely to end up with lost data or missing files (and your precious post processing!) from your catalogue!

Keeping everything backed up

As mentioned above, one of the riskiest aspects of this approach is that it introduces a single point of failure - a mobile hard disk - for all your precious images and Lightroom catalogue. As a result, implementing this solution would be irresponsible without a suitable backup solution in place as well.

There are three aspects to the backup process that must be considered.

  1. Keeping the Lightroom Catalogue backed up locally
  2. Keeping your source images backed up locally
  3. Keeping everything backed up in the cloud

Keeping the Lightroom Catalogue backup up locally

The simplest way to accomplish this is to use the automatic catalogue backup feature built into Lightroom. On both your secondary and primary computers you will be using Lightroom on, set Lightroom to automatically backup your catalogue at a specified interval to a folder located on that computer. It is important that you not set the backup location to be on the same drive as your main Lightroom catalogue (i.e. the external drive).***

After doing this, you will end up with two copies of the Lightroom catalogue backup, one on each of the computers that you are using Lightroom on, in addition to the “canonical” (i.e. main) Lightroom Catalogue on your external drive. This is a good thing, because now your catalogue is doubly protected should something terrible happen to your external drive.
 Note that with this approach there is a possibility that depending on the timing between backups, the two different Lightroom catalogue backups (on secondary and primary computers) may be slightly out of sync with each other. For the most part, as long as you’re regularly using - and backing up the catalogue on - both computers, this should be okay. It might be possible to solve this with other solutions (i.e. making the catalogue backup destination inside of a synced Dropbox folder, for example) but this introduces its own set of problems (first and foremost the significant overhead of storing and regularly uploading tens of gigabytes of Lightroom catalogue backups via Dropbox).

*** To manually specify the catalogue backup location, go under Preferences → Catalogue Settings → Backup Catalogue the next time Lightroom exits.

When you quit, you will be prompted for a location to choose to save your catalogue backup.

Keeping your source images backed up locally

The second problem is how to keep your precious source images safely backup. There are a couple of different approaches, but the one we settled on uses a piece of software known as SyncTime (Mac only) and an backup drive (Western Digital MyBook Duo) - it’s advisable to use an appropriate RAID-type of setup for this.

The setup goes something like this:

  1. Select one of your two devices to be the “master” device - this should be the one with the backup drive connected. (or convenience sake, we’ll assume it’s our primary computer.)
  2. Assuming the backup drive is always connected, create a new SyncTime job to automatically copy the folder containing the source images (and perhaps, for good measure, the Lightroom Catalogue) from the external drive to your backup drive whenever the external drive is connected.
  3. It is advisable to make this a one way sync - i.e. the contents of the external drive always overwrite the contents of the backup drive. This ensures that the latest updates to your external drive are always backed up properly.
  4. Make sure you periodically connect your external drive to your primary computer so that the backup can run regularly.

Keeping everything backed up to the cloud

Discussion of a full-blown cloud backup solution is outside the scope of this conversation (but you can read more about it here) but it should be considered a necessity - the above two backup methods will grant some measure of protection, but a fire, burglary, etc. could still render all your images instantly missing without some form of regularly updated off-site backup.

Keeping Lightroom on an external drive with multiple computers introduces a new wrinkle when making cloud backups - what to use as the authoritative backup and from where and when?

There are several ways to solve this. A more comprehensive, but slightly redundant approach would be:

  1. The external drive is set to backup to its own folder in the cloud whenever it is connected to the primary computer.  This backs up the primary images and the primary catalogue. The first time you do this you’ll need to leave the external drive connected to the primary computer for some time while the cloud backup does its thing, but subsequent backups should be much faster, though may take some time (overnight or more) depending on how much data is being regularly added.
  2. The primary computer’s Lightroom Catalogue backup (which itself is automatically and regularly backed up as above) is set to backup to the cloud in its own folder. This backs up the catalogue backup, just in case.
  3. Finally, the backup drive - which is always connected to the primary computer - is set to backup to the cloud in its own folder. This backs up the source image backups and the catalogue backup, again (if you’ve set it as such above).

Assuming one regularly connects the external drive to the primary computer and has implemented the SyncTime solution from above, it’s possible to get away with an abbreviated version of the above, which trades a small increase in risk for much easier usability and automatedness (the key to a good backup solution).

  1. The backup drive is set to always be automatically be backed up to the cloud. (this assumes the primary computer is always on, and always connected to the backup drive.
  2. The SyncTime job from above is set to always backup both the source images and Lightroom Catalogue from the external drive to the backup drive when connected to the primary computer.
  3. Make sure to regularly connect the extneral drive to the primary computer.

The benefit to this is that the local SyncTime job (syncing the external drive primary images and catalogue to the backup drive) should complete very quickly, which allows you to disconnect the external drive and live your life. In the meaning the cloud backup can complete the much slower upload and backup of your data to the cloud from the now-up-to-date backup drive automatically and in the background, taking however long it needs to complete.

Hardware/Software recommendations

Definitely a “your-mileage-may-vary” and “buyer-beware” situation, but in our case, this is the stack we settled on for this solution.

  • External Drive: Samsung T3 SSD 1TB (Amazon link)
  • Main Backup Drive: Western Digital MyBook Duo (Amazon link)
  • Cloud Backup: Crashplan (Official site) (Read our full-blown backup setup article)
  • External Drive → Backup Sync: SyncTime (App store link)

Conclusion

It’s somewhat time consuming to set up - and not necessarily cheap - but in the end, until Adobe comes up with a more elegant solution, this is the simplest and most efficient solution we have found to enabling to allow multi-computer usage of Lightroom.

Good luck!