# Saving the life of a corrupted catalog



## DLee (Aug 12, 2020)

Hi, I have a large LR work catalog that became corrupted after I moved it to a LaCie mirroring program.

The 135,000 file catalog was originally about 150-200GB in size and living on my laptop, suddenly reduced itself to 14GB after attempting to 'rebuild' the catalog.  Unfortunately the mirrored catalog on the LaCie backup also started reducing itself and I was able to stop it from 'mirroring' at around 90GB.

Every preview is missing except for what's currently connected via HD in either the original or mirrored catalog. Is there any way to save (any of) this catalog before starting to rebuild file by file?

I have one file called TemporaryRepairCatalog Preview.lrdata that is close to 60GB in size.

Is there any way that I can tie this repair catalog into what's remaining of the original LR catalog?

Or do I need to start from scratch and rebuild the entire thing?

My latest backup is about a year old.

Thanks

Dennis


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## Victoria Bampton (Aug 12, 2020)

Previews being missing is no big deal as long as the catalog itself is ok. Try renaming the Preview.lrdata, make sure it opens ok. If it does, when you go to bed tonight, select all and go to Library menu > Previews > Build Standard Sized Previews.


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## DLee (Aug 12, 2020)

Thank you Victoria.

Rename the 'TemporaryRepairCatalog Preview.lrdata' to 'Preview.lrdata?'

Then restart the catalog and see if the missing previews open in a smaller size? Right now every file is a gray black with exclamation mark above it.

Before this happened I came to this site wanting to learn about these files and how they work in regard to LR. Can you tell me which of your ebooks describes all of this?

Thank you.

d


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## Victoria Bampton (Aug 12, 2020)

captdennislee said:


> Right now every file is a gray black with exclamation mark above it.


Oh hang on, an exclamation mark in a rectangle? Or in a black circle?

It's the Missing FAQ that covers all this stuff for Lightroom Classic.


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## DLee (Aug 12, 2020)

It's the exclamation mark in a dotted gray rectangle.
I renamed the Temporary catalog to match the current catalog and about a 3rd of the previews came back.
I have some backups from a while ago is it possible to merge the preview catalogs?
I'll be checking out your Missing FAQ's ebook, but I have a feeling I've lost about 12 years of work here. At least the catalog appears to be good order and still has all my 'collections.'
Any suggestions are appreciated. Thank you.


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## DLee (Aug 12, 2020)

I have a more recent LR backup on my Time Machine. It's about a month old. Is there any way to update 'collections' from one catalog to another? 
Or would this need to be a strictly manual process?
What a disaster and all because I was trying to keep an accurate, up to date, copy...


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## Jim Wilde (Aug 12, 2020)

captdennislee said:


> ...but I have a feeling I've lost about 12 years of work here. At least the catalog appears to be good order and still has all my 'collections.'


If the catalog is OK, and the images are still in place, you've lost nothing other than the time it will take to rebuild the previews. Understand that the previews cache can be deleted and rebuilt at any time, they are just previews of the images (and are constantly being updated as images are edited), the crucial data about the edits is stored in the catalog which can then be used to rebuild previews as needed.

However, the exclamation mark indicates that some at least of the images are "missing", and that's what you need to concentrate on first. So, open the catalog and post a screenshot of the left-hand panel in the Library module with the Catalog and Folders Panels open, hopefully we'll see an obvious and easy-to-fix issue.


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## DLee (Aug 12, 2020)

Thanks Jim. I feel like my biggest problem is not understanding the hierarchy and labelling of the preview caches. I have backups of entire catalogs at different periods of time that have Previews from all the older work, I just do not know how to re-combine them into one coherent catalog... or if that's even possible.

The files live in my LR catalog primarily as Smart previews as the originals are spread out over 20+ hard drives spanning at least 12 years. This is a perfect time for me to re-organize all of these file and accumulate ALL the folders and images in one place... or as much as 4TB can hold.

What I would really like right now is to be able to just get the catalog back up and running with all the preview images (and not blank gray boxes) in case the client needs something. Know what I mean? I can always connect to the original folder and rebuild Smart or 1:1 previews, but with pages and pages of gray it's hard (not impossible) to know where stuff is. Fortunately I have a pretty extensive 'collections' section where I can locate stuff in general terms.

I really wish I understood how I might use these older preview folders I have at hand.

I hope that helps explain my situation.


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## Roelof Moorlag (Aug 12, 2020)

captdennislee said:


> I feel like my biggest problem is not understanding the hierarchy and labelling of the preview caches.


I can understand that but for now these previes caches are not important at all. As Jim pointed out, these can be rebuild.
Those exlamation marks are to worry about however. Focus on that first and the rest later.

Two things are important; the catalog (the .lrcat file) and the images. If you have backups of both, you don't have to worry to much. 
As Jim asked; post some screenshots


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## DLee (Aug 12, 2020)

Roelof Moorlag said:


> I can understand that but for now these previes caches are not important at all.
> 
> Two things are important; the catalog (the .lrcat file) and the images. If you have backups of both, you don't have to worry to much.
> As Jim asked; post some screenshots



Ok, I'll post the screen shot below.

I think you guys are failing to understand my dilemma. I am not worried about the files, they are backed up and fine. The recent .lrcat appears fine and I have a couple backups of it. What I'm missing is all my previews. I know that previews can be rebuilt, but look at all those hard drives on the left. 

Is there any way to combine Preview caches from previous copies of this LR catalog to rejuvenate the missing Previews without rebuilding them from the original files? 

For example. I have a complete copy of the catalog from October 2019 that has all my previews for missing older stuff intact. Is there any way to take those preview caches and add them to the current LRCAT that I am rebuilding to regain the missing previews?

Thanks,

d


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## DLee (Aug 13, 2020)

So for example. Here are files from a copy I made of my working LR catalog back in October 2019.  I had to upgrade the catalog (yellow dot) to the current LR version (green dot).

Could I take this large file:  Smart Previews 2.lrdata  (5/6/14) 110.82GB and add these Smart files to the catalog I am rebuilding?

Would I need to take Helper.lrdata or other files along as well?

Could this possibly work? If so, what would I need to do regarding changing names etc?

Thank you.


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## DLee (Aug 13, 2020)

Is this type of information covered in Victoria's Lightroom Classic Missing FAQ book?

thanks


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## Roelof Moorlag (Aug 13, 2020)

captdennislee said:


> think you guys are failing to understand my dilemma.


I think its the other way arround, you are missing rhe point. Those preview files do not offer you a quick sollution. So don’t bother and let them simply rebuild again. It only does take some time.


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## DLee (Aug 13, 2020)

Roelof Moorlag said:


> I think its the other way arround, you are missing rhe point. Those preview files do not offer you a quick sollution. So don’t bother and let them simply rebuild again. It only does take some time.



No offense Roelof but I don't think you looked at my catalog. There are over 139,000 files on 14 different hard drives... No, being able to re-install existing Previews would be MUCH easier.

I just spent over two hours reinstalling one hard drive. The previews haven't even been built yet. Dragging and relabelling a Smart Preview file with 110GB worth of previews in it would definitely be the way to go. I just don't know how to do it.

d


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## PhilBurton (Aug 13, 2020)

captdennislee said:


> No offense Roelof but I don't think you looked at my catalog. There are over 139,000 files on 14 different hard drives... No, being able to re-install existing Previews would be MUCH easier.
> 
> I just spent over two hours reinstalling one hard drive. The previews haven't even been built yet. Dragging and relabelling a Smart Preview file with 110GB worth of previews in it would definitely be the way to go. I just don't know how to do it.
> 
> d


As someone with no "dog in this fight," I think you would better served taking a conservative approach.  I concur with Roelof here.

If you search my postings, I did a writeup about a year ago explaining how the OP for this thread could consolidate six drives' worth of photos onto one much larger hard drive.  In your case, you  might need a RAID array for your storage needs.  Western Digital now makes 12 and 14 TB desktop (3.5") drives, and you can save money by buying a RAID enclosure and populate it yourself.

Yes you would be left over with those other drives, but to me 14 drives is a logistical nightmare, especially for backup.

Phil Burton


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## DLee (Aug 13, 2020)

Phil, since nobody is giving me advice on 'HOW' to re-instate the Preview and Smart Preveiw files that  I have, I am forced to take this approach.

I agree with you though that having it all together in one place is a far better solution and that is what I have begun to do. On a new 4TB HD I have the catalog and am copying all files onto that same drive. It's a laborious process. First transferring the data to the new drive then assigning the images to the new location. In the long run I think it will be worth it but it's very time consuming at the moment. I'm working newest to oldest. Since work is scattered throughout the 14 former drives the 4TB could come close to being enough space. Fingers crossed.

For the time issue and a general dislike for the way the new technique is associating the files in the 'Folders' portion of LR I am also rebuilding another copy of the original LR catalog in it's original form. This does go faster and as Victoria suggested I will just let it run through the night building previews at 2 stars and above.

The biggest puzzle to me is 'how did this happen?' I have to assume it was the LaCie mirror backup that corrupted the file and then somehow erased a huge portion of the data. The original catalog had to shut down for a corrupted file, which I hardly ever saw before. But it had been happening ever since I put it in the LaCie mirror folder for backup a week or so ago.

I set LR to work rebuilding/fixing the corrupt file on my computer and when I came back my 190GB LR catalog was 14GB! I immediately shut down 'mirroring' to the HD but it was too late. The duplicate had also been depleted by close to 100GB. I have no idea where all the data went. I noticed it because the computer had been running low on free space (about 15GB) and I had the Picture folder open and it said there was 175GB available on the computer! You might be able to imagine my panic. This is just another punch in the terrible streak of bad luck I've been having... I barely care anymore, it's the wasted time to rebuild that really sucks. There is other work to be done.

But the question remains, where or where did it go?

d


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## Jim Wilde (Aug 13, 2020)

Just for the record, you cannot "merge" existing preview caches, all you can do is replace the current cache with a different version of the same cache to see if that helps at all. So rebuilding makes the most sense to me, though I understand the difficulty that would cause if you have the original files spread over 14 different drives which are not always online. However, I assume you can connect several drives at the same time, in which case a methodical approach to rebuilding both caches would be the approach that I would take.


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## DLee (Aug 13, 2020)

Jim Wilde said:


> Just for the record, you cannot "merge" existing preview caches



Thanks Jim, that's what I had been wondering.  I see some cache's followed by the number two and I thought they may be consecutive sets of previews. But I guess not. Which is to be discarded? The one that ends in Smart Previews.Lrdata or the one that ends in Smart Previews 2.lrdata?

Also, what is the significance of the LR catalog saying 'readOnly'?

I'm rebuilding the cache now on the repaired catalog. I figure it will take a few good nights. I'm also creating another version of the catalog that will have all the files on board on the same drive. The latter will take more time but will get there eventually.

Thanks to all who commented here.

d


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## Jim Wilde (Aug 13, 2020)

The caches names reflect the catalog name.....so if you have a catalog named Lightroom Catalog-2.lrcat, the library preview cache will be named Lightroom Catalog-2 Previews.lrdata, and the smart previews cache will be Lightroom Catalog-2 Smart Previews.lrdata. The "-2" on the catralog name happens whenever the catalog is upgraded during a version upgrade......it's not untypical for catalogs to have names ending "-2-2-2-2".

I would think that the "readOnly" bit is user added, not added by Lightroom.


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## clee01l (Aug 13, 2020)

captdennislee said:


> No offense Roelof but I don't think you looked at my catalog. There are over 139,000 files on 14 different hard drives... No, being able to re-install existing Previews would be MUCH easier.


. Previews are not important in the long term.  In Catalog Settings, there are settings to determine the standard size, quality and the retention period of 1:1 previews.   Lightroom can automatically discard 1:1 previews in as little as 1 week. 
You have a catalog of ~140,000  images.  There is no need to have a preview available (and taking up disc space for all 140.000 images.  You just need previews for just the ones that you might look at on a short term basis (during processing).   Once you are finished with the day to day use of the image and have exported or printed these, you really don't need a preview for something that you might never look at again.   If you do need to pull up an old image (for a new print or new export.  Lightroom will build the needed preview on the fly.   So, in short, you don't need ~140,000 preview images in three sizes.  Your panic to recreate Previews is unwarranted.   As long as your master catalog file is intact and there are backup copies of that master catalog file ("*.lrcat") you will not lose anything that Lightroom can't recreate from your master image files as needed BY LIGHTROOM.


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## DLee (Aug 13, 2020)

Cletus, I appreciate everyones feeling that Previews can be easily rebuilt, I understand that, but why doesn't anyone agree that being able to drag a backup preview file in place would be quite simple if possible.

This is an entirely client based catalog that gets referred to constantly, secondary files are re-evaluated all the time as tastes and needs change.

I'm rebuilding this catalog by making Smart previews for everything 2 stars and above. But really I'll eventually want to get back to one star selects as well.

It's a lot of computer time that could be spent doing other work. It just fascinates me how quickly you all say to 'rebuild' rather than 'Yeah, you can use that 100GB Preview file you saved a month ago by doing this and this... and save hours of work'  I mean it's the first recommendation that Victoria made but I don't have the background to understand her short explanation.  So I'm spending hours here rebuilding instead.  Ridiculous if you ask me. No offense, but why don't you guys get this?


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## clee01l (Aug 13, 2020)

captdennislee said:


> Cletus, I appreciate everyones feeling that Previews can be easily rebuilt, I understand that, but why doesn't anyone agree that being able to drag a backup preview file in place would be quite simple if possible. .


Previews can easily be rebuilt is why



> This is an entirely client based catalog that gets referred to constantly, secondary files are re-evaluated all the time as tastes and needs change.
> 
> I'm rebuilding this catalog by making Smart previews for everything 2 stars and above. But really I'll eventually want to get back to one star selects as well.


Previews Are NOT a part of the Catalog. You are rebuilding the Previews and as many have pointed out the previews are not needed for every file





> It's a lot of computer time that could be spent doing other work. It just fascinates me how quickly you all say to 'rebuild' rather than 'Yeah, you can use that 100GB Preview file you saved a month ago by doing this and this... and save hours of work' I mean it's the first recommendation that Victoria made but I don't have the background to understand her short explanation. So I'm spending hours here rebuilding instead. Ridiculous if you ask me. No offense, but why don't you guys get this?


 You said it your self, “It's a lot of computer time that could be spent doing other work”. Ignore the Previews issue. It was never an issue. Lightroom will rebuild the previews that IT needs when you request an image in Loupe or grid view. It takes very little time to do this while you are using Lightroom Classic. Or You can Select images in your master catalog and rebuild previews overnight from the menu bar. The Only preview folder that you need is the one that is named for your Master Catalog file. The others in your list only take up unnecessary disk space. 
In the time that you have spent already you could have rebuild the Previews folder for your master catalog 




Sent from my iPad using Tapatalk


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## DLee (Aug 13, 2020)

Cletus, if the catalog is not tied to a hard drive supporting the files, which mine almost never is, Smart Previews are a very big deal and yes, they are needed for every file that I may want or need to look at.

The process of rebuilding is happening now and will be complete soon enough. My point, again, is that had someone helped me understand how to rename and load a 'saved' Smart Preview file I would have moved it over and just updated the most recent work. I could have been done an hour after the purge.

But, nobody other than Victoria suggested that I do that. I thank Victoria because apparently we were on the same page, unfortunately I did not fully understand her procedure so it did not work.

Not everyone works like you do. I will end up with Smart previews for half the files I had before, which will be great space wise. We will have to wait and see how well it works out for me in the long run. It will be like a slim-line catalog which hopefully will be fine.

It just would have been nice to have had some support for doing what I wanted to do and what was recommended by Victoria in the first response, rather than being told by everyone to rebuild, rebuild, rebuild.

I would still LOVE to fully and clearly understand the procedure Victoria outlined in her response. I suspect it could be very helpful in the future. So if any of you guys would share that procedure with me, that would be great. 

Thanks,

Dennis


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## Gnits (Aug 13, 2020)

I agree with Cleetus and all who say you should rebuild your previews. Doing anything else is a massive waste of time, but what is worse, there is no guarantee after all that time that you will have a valid set of previews.

Further, it is entirely possible that the various preview folders you have could contain orphan previews or other rubbish, which will confuse Lightroom when it tries to use it.  

As a matter of routine, I delete all my previews every year or so and let Lr rebuild what it needs.  I have an extremely tidy set up, with my catalog (and previews) on a dedicated ssd drive and all my images on a fast single external drive with lots and lots of spare capacity for future use.  If I had my images spread over 11 drives I would definitely *not *try to manually rebuild my previews.

However, if that is what you want to do then that is your choice.


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## DLee (Aug 13, 2020)

The rebuild is well under way and will probably be complete later today or tomorrow. I am creating a new database at the same time with all the pertinent files in one place and eventually linked to one catalog. I am taking Cletus' advice as mentioned and only rebuilding my top two or three levels of edits depending on content.

I will need assistance when this is all complete on which of the old files to discard.

Thanks. d


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## DLee (Aug 12, 2020)

Hi, I have a large LR work catalog that became corrupted after I moved it to a LaCie mirroring program.

The 135,000 file catalog was originally about 150-200GB in size and living on my laptop, suddenly reduced itself to 14GB after attempting to 'rebuild' the catalog.  Unfortunately the mirrored catalog on the LaCie backup also started reducing itself and I was able to stop it from 'mirroring' at around 90GB.

Every preview is missing except for what's currently connected via HD in either the original or mirrored catalog. Is there any way to save (any of) this catalog before starting to rebuild file by file?

I have one file called TemporaryRepairCatalog Preview.lrdata that is close to 60GB in size.

Is there any way that I can tie this repair catalog into what's remaining of the original LR catalog?

Or do I need to start from scratch and rebuild the entire thing?

My latest backup is about a year old.

Thanks

Dennis


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## prbimages (Aug 14, 2020)

I note that this thread started off talking about "Previews" and then later changed to "Smart Previews". These are different things and may be causing some confusion?

Regarding Victoria's advice, are you referring to her first post immediately following your original post? Where she says "Try renaming the Preview.lrdata, make sure it opens ok"? I read that as a directive to rename the previews directory (which is not the Smart Previews directory) to some other name so that Lightroom won't find it when starting up, thus forcing Lightroom to rebuild its previews. Which is effectively the same advice that everyone else has been offering, isn't it?


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## DLee (Aug 14, 2020)

prbimages said:


> Regarding Victoria's advice, are you referring to her first post immediately following your original post? Where she says "Try renaming the Preview.lrdata, make sure it opens ok"? I read that as a directive to rename the previews directory (which is not the Smart Previews directory) to some other name so that Lightroom won't find it when starting up, thus forcing Lightroom to rebuild its previews. Which is effectively the same advice that everyone else has been offering, isn't it?



If this is the case then wow, all that discussion was for nothing wasn't it? lol. I have no idea. It probably would have been good if someone had pointed this out earlier. Anyway, the 'Smart Previews' have been rebuilt and that catalog is up and running again. The comprehensive gallery is on it's way.

At some point here I will make a small LR catalog for testing purposes only and build previews and then save them, and remove them, and who knows what all. But it's time to learn this stuff. 

Thanks. d


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## DLee (Aug 14, 2020)

I am curious though, what is the difference between Previews and Smart Previews files within the LR hierarchy?


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## Roelof Moorlag (Aug 14, 2020)

captdennislee said:


> It probably would have been good if someone had pointed this out earlier.


?? But everyone did this! I explicit mentioned you missed the point...


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## Roelof Moorlag (Aug 14, 2020)

captdennislee said:


> I am curious though, what is the difference between Previews and Smart Previews files within the LR hierarchy?


The differences between them is pointed out in this blog: Lightroom Performance - Previews & Caches | The Lightroom Queen


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## flyfifer (Aug 14, 2020)

captdennislee said:


> Cletus, if the catalog is not tied to a hard drive supporting the files, which mine almost never is



You say that not everyone works like Cletus does. I'd swap that around. The vast majority of Lightroom users are working in a mode far closer to the way that Cletus does. The way that you work, whereby the drives that contain your all of your images are routinely offline is definitely not typical. Some accept that position on a temporary basis so that they can work on a small subset of their images while working remotely. But I don't know of anyone who so completely relies on smart previews for their entire library because they are never connected to the drive containing the image.

I think that is important to understand. That's why you feel that Lightroom isn't helping you as much as it could, because it isn't really expecting you to have 135k smart previews that are you so utterly reliant upon. You need to understand that the Lightroom hierarchy starts with the catalog at the top and everything is underneath that; the physical image file, the preview and the smart preview. That's why any recovery process needs to be library driven. Adobe make a big issue of all file management of your images needing to be done through the Lightroom application. This is why.



captdennislee said:


> My point, again, is that had someone helped me understand how to rename and load a 'saved' Smart Preview file I would have moved it over and just updated the most recent work. I could have been done an hour after the purge.



Think of it from Lightroom's perspective. It has a catalog file, a preview file and a smart preview file. It expects those files to have the same date because they were all last updated at the same time. Because of some issue that Lightroom does not understand, you now want to bring in a smart preview file that is one month older than your catalog file. So Lightroom automatically knows that there is potential conflict between your smart previews and your catalog. And it has no idea what those conflicts are; images in smart preview but not in catalog, changes made to images in catalog but not reflected in the smart preview, file reference changed in catalog breaking its link to the smart preview.... Only one of those three examples is something that you could fix if you "just updated the most recent work."

Now, you could be lucky, the following workflow *could* work for you:

1. Copy the directory with your library, preview and smart preview files to another directory so you can restore them should this go badly.
2. Delete your preview and/or smart preview file dependent upon which one is really causing you problems.
3. Restore your old backup copy of whichever of those two files you deleted. Make sure that it has the same name as the catalog (i.e. the bit before the file extension).
4. Fire up Lightroom on this instance of your library and see what happens.
5. If it looks OK, force a preview refresh on images that you believe have changed since your backup.

*But*, I can't emphasise how much I would caution using this approach rather than rebuilding your previews. You have no idea how successful you've been until you've tried to do something with each and every one of your 135k photos. And if you discover an entire corrupted album two years down the line, it is way too late to do anything about it at that point.

That's why I would say follow the advice of others here. Force a recovery of the previews from within the Lightroom application itself. It is the only fail-safe solution available to you.


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## PhilBurton (Aug 14, 2020)

flyfifer said:


> You say that not everyone works like Cletus does. I'd swap that around. The vast majority of Lightroom users are working in a mode far closer to the way that Cletus does.


Moreover, Cletus is one of the most respected contributors to this forum.  He is extremely knowledgeable and puts in lots of time answering lots of questions. I personally have benefitted from his advice many times.  You would be wise to pay careful attention to what he suggests, instead of denigrating his responses.

Most newcomers approach the advice given here with respect.  I was slso once a newcomer .  I'm nowhere near as knowledgeable as Cletus, but my Lightroom knowledge has grown and I'm a pretty technical PC user, so I contribute accordingly.  You could also become a contributor over time.  That is why this forum is so great.



> Now, you could be lucky, the following workflow *could* work for you:


Or you might get unlucky and destroy all your catalogs.  Did you have backups of all your catalogs?  (That's also a lot of work if you have 14 drives.)


> *But*, I can't emphasise how much I would caution using this approach rather than rebuilding your previews. You have no idea how successful you've been until you've tried to do something with each and every one of your 135k photos. And if you discover an entire corrupted album two years down the line, it is way too late to do anything about it at that point.
> 
> That's why I would say follow the advice of others here. Force a recovery of the previews from within the Lightroom application itself. It is the only fail-safe solution available to you.



Extremely good advice.

Phil Burton


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## Jim Wilde (Aug 14, 2020)

captdennislee said:


> I am curious though, what is the difference between Previews and Smart Previews files within the LR hierarchy?


The Previews cache contains most of the previews that you will see throughout the interface, particularly in the Library module. Each preview file is in fact a pyramid of multiple differently-sized jpegs, ranging from 1:1 at the top, then standard (sized in accordance with the catalog settings), then various different smaller sizes (for grid, filmstrip, navigator, etc.). So, if you were seeing blank grey thumbnails in the grid, that would indicate that a preview file does not exist. Normally in those circumstances, Classic would automatically create a standard preview....however, if the underlying original image is "missing" (e.g. the containing drive is offline), no preview can be generated, so you're left with the blank thumbnails. When images are online, the user can choose to render either standard or 1:1 previews (1:1 is the same as standard apart from having that additional 1:1 jpeg at the top of the pyramid). Zooming into 1:1 in the Library automatically creates a 1:1 preview.

Smart Previews are used only in the Develop module, and these are a special type of preview which can be used instead of the original when editing images. They are not automatically created, but if they exist for an image that is offline they will allow editing to be done. However, they are only 2560px on the long edge, so some caution would need to be exercised if doing detailed sharpening, for example. The main benefit, of course, it that they allow the travelling photographer to take their laptop with them whilst leaving all their external hard drives containing their images at home. A more recent development allows the user to choose to use the Smart Previews for editing even if the originals are online, on the basis that performance would likely be better when using the smaller smart preview file.


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## DLee (Aug 14, 2020)

Wow, it appears that raising the ire of the community releases the flow of information. Thank you.

I had absolutely no idea the preview/smart preview files might be tied into time stamps with the catalog. In hindsight of course this makes perfect sense.
Thank you Graham for that extremely informative response. Had I been given that information (or linked to it) at the beginning there would have never been any debate or continued questioning on my end. I get it. Although it seems that attempting to do what I proposed could have been at least worth a try on a duplicate catalog... if done correctly.

In the end though, I did take everyone's advice and rebuild the previews. More accurately I rebuilt Smart Previews with Cletus' recommendation of only building the upper echelon.  This catalog lives on my laptops hard drive and indeed often travels with me without associated hard drives which, as Jim pointed out, is why I live and work off of Smart Previews.

Believe me, images spread across 14 drives was not planned, hahaha. It was the result of one job growing into a 12 year relationship with a wonderful company.  But it made me Love working with Lightroom and the Smart Previews. Fortunately my scattered filing system was punctuated by the training I received working at newspapers and I logged all individual shoots by date and subject. This combined with LR's filing system made locating originals very easy when needed. So working with Smart Previews was always really easy for me. The downside of course was a 200GB LR file on my laptop. That file is 20GB now and it will grow as new jobs come in. But, I am perhaps learning how to temper that growth.

So along with getting this 'working' catalog rebuilt on my laptop I have begun building a duplicate catalog on a brand new 4TB HD that will hold as many associated files as the HD volume will allow.  For which I will probably NOT need to build Smart previews, lol. This is something that has been planned for a very long time and because of this 'crash' it's happening. Thank goodness my catalog stayed intact through this disaster.

As a reminder to everyone here. I believe this happened to me because of the LaCie mirroring backup program that comes with their hard drives, it's called Tool Kit. Use at your own risk. 

Which brings me to a very important question. Is there a very good backup program that can back up the daily changes in LR from one drive to another? Specifically for a Mac in my case.

I was reading somewhere here that Victoria worked off of Smart previews (at some point) with her files stored in Dropbox. I thought this was a pretty intriguing idea and I should really look into.

Thanks everyone and I'm sorry if I ruffled any feathers here, it was not the intent. The intent was to not only fix my problem but to begin to understand the hierarchy of the Lightroom file system... and methods for repair and possibly 'trimming the fat' for future reference.  I'm still pretty unclear on this stuff, so any associated links to this information would be greatly appreciated.

Thanks again,

Dennis


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## clee01l (Aug 14, 2020)

Dennis, 
One of the main objectives here in the user led forum is to answer the question asked. A secondary objective is to help users to develop a standard workflow that meets their objectives. 

The question asked was about lost previews and how to go about recovering the images in the Preview folder. Most of the ice in this thread has been addressed to that primary goal. 

Only late in the thread did you reveal your workflow objective and only then did we begin to focus on helping you improve your workflow. 

As an aside, you mention building a new catalog on a noe machine. There is no need to do this and especially NOT to reimport images. 
Your objective as I see it is to develop your master catalog on your master computer including the paths to all of the image files and associated Preview Folder and Smart Preview Folder. 

Once you have that streamlined, you can use a blog article on Victoria’s website on how to move/copy your master catalog to an new computer. 


Sent from my iPad using Tapatalk


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## PhilBurton (Aug 14, 2020)

captdennislee said:


> Wow, it appears that raising the ire of the community releases the flow of information. Thank you.



Excerpting for clarity and focus:

True enough in your case, but most unusual for this forum.  I could even go further  and quote Victoria, "We're a friendly bunch here."   


> As a reminder to everyone here. I believe this happened to me because of the LaCie mirroring backup program that comes with their hard drives, it's called Tool Kit. Use at your own risk.



My career was a field called "software product management, and thanks to the vagaries of companies in IT or High Tech," I've had more jobs than I would have preferred to.  In my experience, most companies, Apple being the noticeable exception, are either good at hardware or software, not both.   To hardware companies like LaCie, software is just an additional expense, to be minimized.  And when you "minimize" the expense of software, you inevietably miminze the quality.

Nikon is a great example of a hardware company with so-so software and a lousy (until maybe recently?) software strategy.  



> Which brings me to a very important question. Is there a very good backup program that can back up the daily changes in LR from one drive to another? Specifically for a Mac in my case.


I'm a PC user, not a Mac user, but a great cross-platform program is File Sync & Backup Software | GoodSync

I use the paid version, and I use it on a daily basis to sync files between desktop and laptop and to sync files between my backup program's hard drive in my system case, and an EHD that is the "backup of the backup."


> I'm still pretty unclear on this stuff, so any associated links to this information would be greatly appreciated.
> 
> 
> Thanks again,
> ...


People on this forum want to help each other.  

Phil Burton


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## DLee (Aug 14, 2020)

Thanks Cletus, 

Either you misread my description above or I was not clear in my writing. I am not moving the catalog to a new computer (at least I hope not anytime soon) but instead building a comprehensive Hard Drive that will contain both the Catalog and ALL (or as many as possible) of the associated files so that they are all together in one place. 

As I write this though I think that maybe I should keep the 'working' catalog on my laptop, and re-associate all the images in the catalog with the new comprehensive file holding HD. I could build Smart Previews for the files that I'm currently working on and the legacy keepers.  The rest would be accessed by connecting the comprehensive HD when needed. This is probably better than having a separate comprehensive catalog on the HD. Wouldn't you agree?

d


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## DLee (Aug 14, 2020)

Thanks Phil, I will check out GoodSynch and see if they make a Mac version.

Your software/hardware comparison is well heard here. I had been shopping for a good program without finding anything with much appeal. When the LaCie program worked without hitch on some simple folders and image collections over time I figured I'd give it a try with the LR catalog. That of course was a huge mistake. Lesson learned.

I appreciate the 'friendly' space as well. My lack of knowledge however, could not wrap my mind around the fact that there was a suggestion to replace and rename a file from one source, the Queen source, and then everyone else said I should rebuild. Now, I understand the complexities (a little better - but not really) and everyone's frustration with my wanting to replace a preview or smart preview file. I get it, I'm over it. I hope your guys are as well.

I really do appreciate all the help. You have all inspired me to move forward here with a better 'working' plan for my LR catalog. Hopefully more current backups as well. hahaha. 

thanks, d


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## DLee (Aug 14, 2020)

Jim Wilde said:


> The Previews cache contains most of the previews that you will see throughout the interface, particularly in the Library module.



Thanks for this concise information Jim, it's appreciated.

d


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## DLee (Aug 14, 2020)

PhilBurton said:


> Nikon is a great example of a hardware company with so-so software and a lousy (until maybe recently?) software strategy.
> 
> I'm a PC user, not a Mac user, but a great cross-platform program is File Sync & Backup Software | GoodSync
> 
> Phil Burton



Phil, I wholly agree with your assessment of Nikon.

Have you used GoodSynch to keep a copy of your evolving LR catalog up to date?

d


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## clee01l (Aug 14, 2020)

captdennislee said:


> Thanks Cletus,
> 
> Either you misread my description above or I was not clear in my writing. I am not moving the catalog to a new computer (at least I hope not anytime soon) but instead building a comprehensive Hard Drive that will contain both the Catalog


But you said


> So along with getting this 'working' catalog rebuilt on my laptop I have begun building a duplicate catalog on a brand new 4TB HD that will hold as many associated files as the HD volume will allow.


Rebuild implies “Starting over”. All of you edits, keywords, collections are in the master catalog. Anytime you “start over” you lose the work in the original catalog. You do not want to do that. 
The “Catalog” refers to only one file, the “*.lrcat” file All other files and folders support Lightroom Classic and the database that is the catalog File. Get your master catalog (File) right on the current machine first, then you move everything to the new computer. You do I not need to “Duplicate” anything. 

I am trying to guide you to use the most efficient methods to achieve your goals. Victoria (the Lightroom Queen) is the expert here and has patiently compiled the most efficient methods working with Lightroom in her books and her blogs. What she has assembled on this website amounts to the collective wisdom of many experienced Lightroom users both within the Adobe community and outside of it. She also has assembled the answers to most of the mistakes that users make in trying to work with Lightroom.


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## DLee (Aug 14, 2020)

clee01l said:


> Rebuild implies “Starting over”. All of you edits, keywords, collections are in the master catalog. Anytime you “start over” you lose the work in the original catalog. You do not want to do that.
> The “Catalog” refers to only one file, the “*.lrcat” file All other files and folders support Lightroom Classic and the database that is the catalog File. Get your master catalog (File) right on the current machine first, then you move everything to the new computer. You do I not need to “Duplicate” anything.
> 
> I am trying to guide you to use the most efficient methods to achieve your goals. Victoria (the Lightroom Queen) is the expert here and has patiently compiled the most efficient methods working with Lightroom in her books and her blogs. What she has assembled on this website amounts to the collective wisdom of many experienced Lightroom users both within the Adobe community and outside of it. She also has assembled the answers to most of the mistakes that users make in trying to work with Lightroom.



Cletus,

Allow me to clarify.

By 'rebuild' I meant 'rebuilding the previews' which I have now completed. I have no plans to move to another computer but  I have said a couple of times that I am going to make a duplicate of this (current, rebuilt preview) catalog on a new 4TB hard drive and collect all the images, in all the folders, on all my other drives, and put them here on the 4TB in one place. All happy, all together. 

Phil has recommended a backup program which will hopefully keep the duplicate back-up catalog on the 4TB up to date.

I hope this clarifies my intentions. If you see any problems with this plan I'm all ears. 

Thanks,

d


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## DLee (Aug 14, 2020)

I do have a question about re-associating all the images in the LR catalog to the new single drive. Should I start a new thread or keep going here?

d


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## Jim Wilde (Aug 14, 2020)

It won't hurt to carry on here.


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## DLee (Aug 14, 2020)

Great, I'm going to make a couple pictures later this evening to help demonstrate what I would like and what I'm getting as I re-assign files.

I think the pictures will explain better than I can writing.

Cheers,

d


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## Roelof Moorlag (Aug 14, 2020)

captdennislee said:


> Which brings me to a very important question. Is there a very good backup program that can back up the daily changes in LR from one drive to another? Specifically for a Mac in my case.


I would take Chronosync for a try. It does have a file validation option and most synchronization applications don't


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## PhilBurton (Aug 15, 2020)

captdennislee said:


> Phil, I wholly agree with your assessment of Nikon.
> 
> Have you used GoodSynch to keep a copy of your evolving LR catalog up to date?
> 
> d


Absolutely.  I use LR on a desktop at home and a laptop out of the house.  I use different GoodSync "jobs" to sync LR settings (on my C: drive), LR catalog (on my D: drive) and bulk photo file store on my E: drive.  For both laptop and desktop, drives C: and D: on on an SSD for performance.  E: is a normal "spinner" HDD.  For the laptop, that's an external WD 4 TB "black" rugged model.  Unlike some of the free PC sync programs, Goodsync is bulletproof reliable.

Of course, the mac has a better designed OS, where you don't need to use this 50-year old drive letter system that goes back to the dates of Intel 8080 personal computers running CP/M, a predecessor of DOS 1.0.

I also use Goodsync to also sync all my other data between systems.  I do NOT sync program installs.  In Windows that would be a big no-no.

For just quick folder by folder comparisons, I use Beyond Compare, from Scooter Software, but I don't think that have a MacOS version.

For true backup, including versioning, I use a commercial backup program called Retrospect. I use Goodsync to sync the backup drive in my system with an EHD that I keep offline, in case I get hit some some ransomware attack that enrypts all my drives.  I'm willing to spend reasonable money on utilities that provide real value.  

Phil


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## clee01l (Aug 15, 2020)

Roelof Moorlag said:


> I would take Chronosync for a try. It does have a file validation option and most synchronization applications don't


TimeMachine is the primary system backup for Macs.  I would recommend that app as it is included free with your OS.  I currently backup 3 volumes to a single (large) backup volume.  (I have 7 EHDs  mounted to my iMac via TB3 and USB3 ports)


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## flyfifer (Aug 15, 2020)

captdennislee said:


> Although it seems that attempting to do what I proposed could have been at least worth a try on a duplicate catalog... if done correctly.



When recovering from a disaster, you always have to ask yourself what is of most importance to you. Is it to get back operating as quickly as possible even if it means you can't guarantee the robustness of the recovered system? Or is it to make sure you are the closest that you can possibly be to having a system that looks like it never had a problem even if it takes longer to get there.

I'm not saying that the first option is never the correct one. My background is in telco billing where I've worked on systems that handle 1 billion call records a day. Those companies are not prepared to be down, and therefore non-revenue generating, for an extra six hours to get that recovery quality guarantee. Even in photography, if you are a sports photographer at the Olympics, you are not delaying submitting your images to an agency by six hours because you want a good recovery. That's a surefire way to making sure nobody uses your images.

But, I'd still suggest that for the vast majority of Lightroom users, quality is more important than speed when it comes to recovery.


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