# What do they mean by "you can only migrate a catalog once"?



## Auz (Mar 17, 2020)

I am experimenting with migrating.  From my master catalog I have created small catalog by using Export as Catalog.  I then migrated that small catalog to Lightroom Cloudy.  I had made a few mistakes in the formation of my catalog, so I decided to try again.  I deleted all the migrated photos from Cloudy.  I corrected my mistakes and re-exported the small catalog.  When I tried to migrate the new copy, it told me you can only migrate a catalog once!  Well, the content of the catalog had changed, but I had re-used the name.  I went back and re-exported the same photos as a catalog, but to a new file name.  This new catalog was migrated with not problem.

Credit:  The idea and method for migrating small parts of my catalog came from a youtube video by Brian Matiash.


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## Jim Wilde (Mar 17, 2020)

What it means is that the migration system is specifically designed to allow a catalog to be migrated only once. Hence the message when you try to re-migrate. There are various workarounds, you appear to have found one of them.


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## Auz (Mar 17, 2020)

That makes perfect sense, Jim, but I was hoping for some deeper information.  How does Lightroom detect that it is re-migrating a catalog?  What exactly could go wrong if it did permit re-migration?  I can guess at these things as well as most, but I hoped someone in the forum might have some unpublished facts.  

My first experiment seemed to suggest that the name of the catalog was sufficient to trigger the migration error--even when the catalog contents were different.  That seems a bit trivial, though, and I suspect there is more going on.  My purpose is to experiment with migration to understand the results better before committing to anything.  Experimenting requires re-doing the same migration with slight variations in the input catalog.


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## johnbeardy (Mar 17, 2020)

I suspect it's more down to the cost of all the extra code that would be needed. For example, let's imagine an image was migrated into Cloudy with a rating of 3, and you then migrated it again but in the meantime you'd changed the rating - either in Cloudy or the same Classic catalogue. You'd need some way to resolve this, which might be as simple as denying the ability to migrate the photo again (ie a photo rather than catalogue-level block) or it might be based on the more recent update time, which is vulnerable because it's not held at the field level.

And no doubt Adobe didn't expect that users would want to repeatedly migrate. So it strikes me as cleaner to  implement this crude block!


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## Auz (Mar 18, 2020)

As a programmer myself, I can easily imagine the difficulties in migrating the same catalog a second time.  As your example implies, it isn't even clear what it should  mean. In my experimental case, of course, there is no problem.  I delete all the migrated photographs from Cloudy before migrating again.  There are copies of the deleted photos being maintained in the cloud (for sixty days) so the second migration is not precisely the same as the first, but that factor didn't seem to affect my migration.


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## fbx33 (Apr 24, 2020)

Why not try deleting the migrated photos from Lightroom, then changing the name of the catalog in Classic and re-migrating? That looks like it might be the simplest way to test the simplest probable answer.


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## Auz (Apr 25, 2020)

That may indeed work.  I'm  not sure whether the name is the critical factor, though.  Lightroom may put some kind of mark inside a migrated catalog that keeps it from ever being migrated again.  I've stopped experimenting, so someone else will need to test it.  Maybe you?

After my experiments I decided against migrating for now.  Instead, I'm using Lightroom as my application for new work and I intend to do all my culling, editing, and metadata entry there.  I use sync to get the photos copied into my master catalog in Classic.  I'm happy with this workflow  so far.   (I am not keywording, obviously, which is a sad issue.)


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## fbx33 (Apr 25, 2020)

Thanks, may do. I'm still using Classic as main app. I keep trying to look at Lightroom (Cloud) but many of the things I tend to use (masks, for example) don't seem to be there.

And the editor in the 3rd Lightroom (lightroom.adobe.com) is pathetic. I can't see what the point of it is.


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## Victoria Bampton (Apr 25, 2020)

You can Export as Catalog into a new catalog if you needed to migrate again.


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## fbx33 (Apr 28, 2020)

Hi Victoria and thanks for all your work on LR. It is, as you must know, essential for all LR folk. 

This morning I added an external drive and set it as the location to make the Lightroom copies for migrating my Classic catalog to Lightroom. I want to get all my  full size images into the Adobe Cloud. 

However, I already have sync'd images in Lightroom as *LOCAL: Smart Previews* and *CLOUD: Smart Preview Only*.

I'm wondering is the MIGRATION will overwrite those with full size versions of same pictures, or if I have to do something else (delete all Smart Previews?) before the Migration will work properly.

I started this at 1 this afternoon and after 12 hours or more doesn't't seem like a lot has happened. I do have a few files now marked as *Synced & Stored Locally *with the blue circled below right of the thumbnails and that *LOCAL/CLOUD: Original* in the Sync Status panel. Also the cloud icon in upper right corner of Lightroom page has the blue circle moving in I, going around and around, slowly.

I don't see anywhere I can get a report of progress like number of files moved or whatever, so I'm nervous that the migration may not be working correctly. At this rate I expect it will take weeks to move the 27K files to the cloud and Lightroom from Classic?

So, does this sound right or wrong to you, I mean should I quit and start over or just let it ride? Getting nervous down here in Florida.

fbx


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## Victoria Bampton (Apr 28, 2020)

That sounds perfect, if the dialog has gone, then they should be in Lightroom's local storage but it can take ages to upload them to the cloud depending on your upload speed.


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## fbx33 (Apr 28, 2020)

Thanks much. Will continue waiting.  Appreciate your speedy reply.


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