How long to save Backups and Catalog Previews?

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Ollie

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I'm currently using LTR 2.7. LTR Backups and LTR catalog previews are saved on my primary internal hard drive (the C drive). Checking memory space today I noted that backups, which go back almost two years, occupy 167GB of space (50,241 files in 37,323 folders). Catalog previews occupy 24.3 GB, containing 80,384 files, going back to the same date, almost two years ago. I clicked on the oldest preview. A window opened asking me if I wanted to relaunch LTR with this catalog. Why would I want to relaunch with anything other than the latest? Which made me wonder, why am I keeping all those old catalog previews? Is there any reason not to delete all but the most recent, and free up the storage space?

And the same question for the much larger Backups folders. I periodically backup LTR when I open it; nowadays it's taking maybe half an hour, which makes me think it's backing up everything. So why keep those old backup folders? Won't the latest backup save my data?

All of my "Master" files are saved in duplicate on two separate external hard drives.

Many thanks for comments.
 
Ollie welcome to our forum.
If you accidentally delete images from the catalog, you will need the last good catalog backup to recover that part of the catalog that was inadvertently deleted. So, how far back in time is that? I don't know either. But I have gone back over two months to correct such a blunder. I don't know how frequently you have your catalogs set to backup, but I figure once a week is enough. If I delete image files and catalog data that is less than a week old, I feel confident that I can recover easily enough by just reimporting the originals.
So while you probably don't need to keep 2 years worth of catalog backups. You need to keep as many as your risk comfort level can tolerate. Everyone's risk toleration is different, so you will need to be your own judge of what is right for you.
 
Ollie welcome to our forum.
If you accidentally delete images from the catalog, you will need the last good catalog backup to recover that part of the catalog that was inadvertently deleted. So, how far back in time is that? I don't know either. But I have gone back over two months to correct such a blunder. I don't know how frequently you have your catalogs set to backup, but I figure once a week is enough. If I delete image files and catalog data that is less than a week old, I feel confident that I can recover easily enough by just reimporting the originals.
So while you probably don't need to keep 2 years worth of catalog backups. You need to keep as many as your risk comfort level can tolerate. Everyone's risk toleration is different, so you will need to be your own judge of what is right for you.

I read Ollie's post and wondered about something, and perhaps if I was doing something wrong?

In my setup, I do not see 'previews' being included in the Lightroom backup routine? My backup files, which are run every time I exit LR, contain only the catalog file. When he said "I click on the oldest preview", I assume he meant 'catalog'?

I have my preview settings at the largest size, highest resolution, and to never discard. I suppose I can modify that at some point, but for now, I have the capacity to handle the data load, which is substantial with a catalog of 25,000 images, creating about 134 gb of preview data.

Since I am slowly converting from Aperture to Lightroom, as well as adding a considerable amount of analog material, I expect the catalog to grow considerable, perhaps by 10 times.

I have had a bit of a discussion on this forum, with Victoria, about the thinking around including or excluding the catalog files from my regular Time Machine and other backup routines. My current set of backup files, which only go back a little over a month, account for about 14 gb of data. I have yet to determine how long to maintain those files, in light of the fact that they themselves are backed up in three other locations. Time Machine needs at least a month before lesser versions become permanent in its archive.
 
Previews are generated as needed by LR fron the master original image. LR does not keep previews forever and will discard older ones as some magical disk space limit is reached. Previews can take up GBs of disk space and duplicating the previews make little sense when they can be regenerated as needed by LR.

If you like, You can delete your preview folder at anytime and LR will start to build a new one from scratch immediately. This will happen in the background and be completely transparent to you except for a slight delay when LR needs an image to display on the screen and there is not a current preview available.

I exclude the LR catalog and the LR Previews folder from the Time Machine backup. I do let TM backup my LR catalog backups. I do not need a TM backup of the current catalog or the Previews. As has been mentioned elsewhere, the LR catalog may be open at the time TM runs and might be in an unstable state. TM may not even backup this active catalog if it is open
 
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You're quite right, previews are not included in the backup routine - they'd take up HUGE amounts of space, especially in a versioned backup, as they change so frequently. As long as you've got the original photos, you can easily rebuild the previews.
 
I read Ollie's post and wondered about something, and perhaps if I was doing something wrong?

In my setup, I do not see 'previews' being included in the Lightroom backup routine? My backup files, which are run every time I exit LR, contain only the catalog file. When he said "I click on the oldest preview", I assume he meant 'catalog'?

I have my preview settings at the largest size, highest resolution, and to never discard. I suppose I can modify that at some point, but for now, I have the capacity to handle the data load, which is substantial with a catalog of 25,000 images, creating about 134 gb of preview data.

Since I am slowly converting from Aperture to Lightroom, as well as adding a considerable amount of analog material, I expect the catalog to grow considerable, perhaps by 10 times.

I have had a bit of a discussion on this forum, with Victoria, about the thinking around including or excluding the catalog files from my regular Time Machine and other backup routines. My current set of backup files, which only go back a little over a month, account for about 14 gb of data. I have yet to determine how long to maintain those files, in light of the fact that they themselves are backed up in three other locations. Time Machine needs at least a month before lesser versions become permanent in its archive.

JG: You're right. I should have said "catalog."
 
Cletus: Many thanks. Sounds like I can easily delete most of that 167GB now being used to hold catalog backups, keeping maybe just the last three months or so.

Maybe I shouldn't ask about things I maybe don't need to know, but I took a closer look at the folders under the LTR Previews folder. There are folders named 0 (zero) to 9, followed by A to F. Several on which I looked at "properties" apparently have 4000+ files in each folder. But what puzzled me was that "Properties" showed every one of these folders as "Created May 8, 2009." (I bought LTR2 in January 2009. I doubt that I waited till May to install it, but I really don't remember.) So I don't really know what I've got in any of the folders and am not sure what I would be deleting if I deleted them. When I tried to open them Windows told me it didn't recognize the file. Should I just assume that the one at the bottom of the list ("F") is the most recent? I do get the point from reading other comments that preserving the previews doesn't seem to be very important, so there's some more GBs I could free up, if I knew which ones to delete.

One other question: "Properties" tells me I have 50,241 files in 37,323 folders in the Catalog Backups folder. Why the disproportionately high number of folders compared to the number of files? Thanks again for helping explain the mysteries of Lightroom.
 
You can safely delete all of the backed up preview folders. LR will, if and when its necessary, automatically recreate the previews.
 
"Properties" tells me I have 50,241 files in 37,323 folders in the Catalog Backups folder. Why the disproportionately high number of folders compared to the number of files? Thanks again for helping explain the mysteries of Lightroom.
Your backup folder should contained one date named folder for every backup copy of your catalog. If you should have opened a backup catalog by mistake in its backup location, LR will create a previews folder with lots of (mostly empty nested) folders and preview files. So if you have more files than folders, it suggests that something like that has happened in the past. You might want to make sure that are not some catalogs with missing edits hidden in the backup folder before you delete them carte blanche.
 
You may also want to tell LR to place the backup catalogs on another disk than C: (if you have another disk). Storing backups on the same disk as the original is a poor backup in case the disk fails, thus loosing both the original and the backups. If you only have one disk though, you have no choice.
 
Just though I would come in on this thread. After reading it I started to delete backups, on deleting one from March 2012 it says it is recycling several thousand items, is this OK.

jeff
 
Hard to say, Jeff. What exactly are the several thousand items being deleted?

There are only three places I can think of offhand, where Lr has data on the order of 'several thousand items'.

1) The Library preview cache, in the folder/package catalog_name.lrdata
2) The Adobe Camera Raw cache, which you can locate in the Lightroom Edit>Preferences>File Handling dialog
3) The actual image files.

None of these are backed up by Lr's automated procedure, so what's happening would just be guesswork at this point.

If you don't know what the files were, have a peek in the recycle bin, and see what it's full of.
 
Possibly not. Your back up folder created by LR should consist of a folder named for the day of the backup and a copy of your master catalog as it existed on that date. There should be nothing else in it. It is possible that you inadvertently open a Backup catalog by mistake and in doing this you created a previews folder and possibly imported master originals into the backup folder. You need to make sure that none of your master original image files are missing in your current master catalog before we can say for certain that everything else in the backup folder is expendable. Personally, I would never delete a folder without verifying the contents first.
 
.... It is possible that you inadvertently open a Backup catalog by mistake and in doing this you created a previews folder and possibly imported master originals into the backup folder. .....

Aha, I didn't think of that one, Cletus. That likely explains the situation. Fingers crossed, that nothing valuable is missing.
 
Jeff, please stop what you're doing immediately!

If that screenshot of the Catalog Settings is the catalog that you have been using (and looking at the "last backup" date it certainly looks that way), then you may have been using that backup catalog as your prime catalog for who knows how long. So until you sort this out, stop trying to delete that folder (yes, it's a folder, not a file).

In Lightroom, do File>Open Recent and please take a screenshot of the list that is then shown. Don't select any, just post the screenshot and let us have a look so we can try to untangle you.

Also, can we have a screenshot of that "Backups" folder, but this time showing the bottom of the display rather than the top. Thanks.
 
Thanks. Could I have a couple more please:

1. An Explorer view inside that 2012-04-28 0033 Folder (Details view).
2. The General Tab of the Lightroom Preferences (Edit>Preferences>General Tab).

Can you tell me (approximately) when you upgraded to LR4? And did you upgrade your LR3 catalog, or start with a new LR4 catalog? I'm guessing the latter, because it looks like it was a backup catalog that you had open when the upgrade was done, so the LR4 catalog was created in the LR3 backups folder (i.e. in the 2012-04-28 0033 sub-folder). Those screenshots will confirm.
 
Took a bit of searching but I purchased LR4 on 28 Aug 2012 so would have installed it soon after.

jeff
 
Took a bit of searching but I purchased LR4 upgrade on 28 Aug 2012 so would have installed it soon after.

jeff
 
Thanks. As you can see, your LR4 catalog is actually in that backup sub-folder (so it's just as well you didn't proceed with that deletion!!). No real harm, fortunately, but I would suggest you correct the situation ASAP. Close Lightroom, then use Explorer to drag the "Lightroom 4 Catalog.lrcat" and the "Lightroom 4 Catalog Previews.lrdata" from out of that sub-folder and drop them on the "Lightroom" folder 2 levels up (so they'll no longer be in any "Backups" folder). Then double-click on the "Lightroom 4 Catalog.lrcat" in its new position, that will open Lightroom again, then I suggest you go and change the startup option in the Preference>General Tab.....this issue started because you opened that 2012-04-28 backup catalog to check on something, but because your preference is to "Load Most Recent Catalog" you carried on using it up until your LR4 upgrade, but the new LR4 catalog was placed in the same backup sub-folder. I really don't like that "Load Most Recent Catalog" setting, it's too easy to make that mistake (plenty of others have), so I'd suggest changing it to either load the specific LR4 catalog or select "Prompt me....." (though the latter is really only for those with multiple catalogs).
 
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