Unwanted copying of data from external to internal memory

I have just moved into my firstMac, a Mini M4 24GB UM, 512GB Internal plus a 2TB External SSD running Tahoe. I moved my data manually, placing a big folder of image files and a 20GB folder named myDocuments which is by it's nature a bit of a ragbag, containing assorted document files and associated images.

All apps present are fresh installations. I put Photoshop and Lightroom in their own folder entirely separate from Mac Photos as I envisaged possible file ownership and catalogue issues. So far this has been successful.

Yesterday I added an external HDD for Time Machine and created my first backup - and then decided to have a bit of a look round and check that all was neat and tidy - that was when I realised that the entire contents of 'myDocuments' had been copied into 'Documents' on the internal drive. (I verified that by dismounting my external drive and opening a few files!)

I was aiming for a fairly traditional configuration - data stored externally, apps installed internally, with the rest of the internal 'space' available as a working area. That may seem excessive, but some of the functions Adobe includes these days are resource hogs, so there's future proofing to consider!

Basically, I don't want these files on the internal disc. I thought that giving my created holding folder a unique name would be enough to keep them distinct. It wasn't, so presumably if I just delete the contents of Documents, they will soon reappear... So what should I try next, Please?

Mac mini, macOS 26.2

Posted on Jan 23, 2026 7:01 AM

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Posted on Jan 26, 2026 6:38 PM

DavidP225 wrote:

I have to confess that when I first read your comments I didn't really feel that they applied to me as I have rather less than no intentions to sync anything to the Cloud. It could be an age thing, but the merits of storing stuff that is personally important, in a semipublic location over which I have no control but is probably quite visible to assorted evildoers, have never been apparent to me. And the thought of being unable to access my data because some public works contractor has severed some optic fibres... Let's not dwell on that one!


The problem here is not that we think that your data would "probably [be] quite visible to assorted evildoers" or that we think it would be likely that you would be "unable to access [your] data because some public works contractor has severed some optic fibers."


It is that the synchronization and update mechanisms that many applications use to update complex databases don't mesh well with the way that network drives work, or with the way that cloud drive services such as iCloud Drive, Google Drive, or Microsoft OneDrive work. We're not talking about "evil hackers" corrupting your data … but about your own applications, under your own control, potentially corrupting it, or causing updates to involve massively more data writing than you expected, for technical reasons.


You do not need to keep your Desktop and Documents files in iCloud Drive, and if you aren't doing that, they are going to be as local as any of your other folders (like Pictures). But now that Apple has put this feature in macOS, it might be turned on without you realizing it, or you might one day go and turn it on without realizing the effect it could have on complex databases (as opposed to simple files).


Add your Desktop and Documents files to iCloud Drive - Apple Support


You're saying Pictures would be safer? So be it (sighs!).


Yes, because as far as I know, it will be a strictly local folder regardless of whether you are using the other feature or not. Which means that applications that are expecting the filesystem to have all of the characteristics that they expect from a Mac filesystem on a directly-attached storage device will have those expectations satisfied.

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Question marked as Top-ranking reply

Jan 26, 2026 6:38 PM in response to DavidP225

DavidP225 wrote:

I have to confess that when I first read your comments I didn't really feel that they applied to me as I have rather less than no intentions to sync anything to the Cloud. It could be an age thing, but the merits of storing stuff that is personally important, in a semipublic location over which I have no control but is probably quite visible to assorted evildoers, have never been apparent to me. And the thought of being unable to access my data because some public works contractor has severed some optic fibres... Let's not dwell on that one!


The problem here is not that we think that your data would "probably [be] quite visible to assorted evildoers" or that we think it would be likely that you would be "unable to access [your] data because some public works contractor has severed some optic fibers."


It is that the synchronization and update mechanisms that many applications use to update complex databases don't mesh well with the way that network drives work, or with the way that cloud drive services such as iCloud Drive, Google Drive, or Microsoft OneDrive work. We're not talking about "evil hackers" corrupting your data … but about your own applications, under your own control, potentially corrupting it, or causing updates to involve massively more data writing than you expected, for technical reasons.


You do not need to keep your Desktop and Documents files in iCloud Drive, and if you aren't doing that, they are going to be as local as any of your other folders (like Pictures). But now that Apple has put this feature in macOS, it might be turned on without you realizing it, or you might one day go and turn it on without realizing the effect it could have on complex databases (as opposed to simple files).


Add your Desktop and Documents files to iCloud Drive - Apple Support


You're saying Pictures would be safer? So be it (sighs!).


Yes, because as far as I know, it will be a strictly local folder regardless of whether you are using the other feature or not. Which means that applications that are expecting the filesystem to have all of the characteristics that they expect from a Mac filesystem on a directly-attached storage device will have those expectations satisfied.

Jan 23, 2026 11:09 AM in response to DavidP225

DavidP225 wrote:

I understand that Documents is what would be described as a system folder in PC circles - and not to be messed with.

It's the opposite. The Documents folder is where you should store all of your documents.


I did manage to Incapacitate a system folder once

That can't happen on a Mac. All the system folders have very tight protection on them.


Photoshop and Lightroom are in a folder within the Applications folder along with the working catalogue and seem to be working fine.

What do you mean by "the working catalogue"? Those are 3rd party apps, do I don't know how they work. But generally speaking, only apps should be inside the Applications folder. The applications folder can have slightly more restrictive permissions on it. It's meant to be accessed by all users on a computer. But if one user puts files there, then other users may or may not be able to access them, which may or may not be a good thing, depending. It's better to put documents in the Documents folder.


The only caveat for this is if you're using iCloud Drive with Desktop and Documents. That might not be appropriate for data packages. I'm thinking of things like a Music library or the Photos database. That's why those are not in the Documents folder, on purpose. I don't know about Photoshop and Lightroom. If they use any kind of self-contained database, then they shouldn't be in either Applications or any kind of sync-controlled location like Documents (or Desktop or iCloud Drive, or 3rd party cloud location).


What is bothering me is the apparent 'Data Grab' by Documents. If it turned out to be almost impossible to divert the output of Pages, for example, that might be inconvenient but not puzzling. It's the copying of a whole file tree from another drive that concerns me - I've always understood that folders were passive repositories, but perhaps this one isn't so passive.
I'm reasonably confident that I haven't done anything to trigger this copying, but no guarantees!

I'm less confident. 😄 The only way that Documents will be automatically populated by anything is if you are using some kind of cloud sync service like iCloud or some 3rd party service. Even then, you would have to explicitly set it up to run that way.

Jan 23, 2026 7:38 AM in response to DavidP225

What you're doing is reasonable-- there's nothing wrong with keeping stuff on an external drive. You can even boot off an external drive, but that can be rather slower. I'm a bit confused about why you're asking this in the Photos Community. Is there something special happening with Photos? You don't say if you are using iCloud Photos or iCloud Drive. iCloud Drive must be on the internal boot drive.


How is your external drive formatted? Certainly for Photos, and maybe for other apps, an external drive must be formatted in either the modern APFS format or in the older Mac OS Extended (Journaled) format. The drive must be connected directly to the Mac by cable, not networked, clouded, NASed, etc. Additionally, the drive can not have had Time Machine on it since it was formatted. See this:

Move your Photos library to save space on your Mac - Apple Support

If this drive is in a an incompatible format, stop running Photos with it immediately!  A Photos Library can sit on an incompatible drive, but running it may corrupt the database.


"Documents" and "Desktop" are special folders on a Mac. Apps often put their data there by default, and of course the contents of the Desktop folder shows up on, well, the desktop. These two special folders must be located in your User folder, unless you especially choose in System Settings to locate them in iCloud Drive.


Normally the apps like Photos, Lightroom, and Photoshop are kept in the Applications folder on the internal drive. I can't think of a good reason to put them someplace else. Adobe can be weird about where it stores data-- some is kept with the app, but data defaults to Adobe albums in the Documents folder, I think, though I don't see any there-- I think I moved the default catalog and stuff. A Photos Library can be kept in pretty much any non-special folder, and it's fine on a properly formatted external drive.


It's OK to have a folder named myDocuments. You can also have a folder named Documents someplace other than the User's folder or iCloud Drive, and it will be treated like other generic folders.


I'm not sure how much of this you already know or if it even applies to your problem, but it's a start…


Jan 23, 2026 8:47 AM in response to DavidP225

How exactly did you "move" into your first Mac?

What steps did you follow? Did you use any app or tool to move over? Was this from a Windows PC? IF so, did you use Migration Assistant?


If you use the Migration Assistant with a Windows PC, then by definition it will copy everything in the selected user folder to a new user on the Mac. This includes any files and folders in that user folder, so if your myDocuments folder was there during migration it would have been copied over.


Beyond that there is no way for it to just magically copy a folder onto the Mac unless you manually do so. So what exactly did you do after connecting the external drive to the Mac?


You are assuming many things incorrectly. The Mac does not just appropriate folders on external devices based on name. Something else had to happen.


You will need to really explain what you did step by step, so we can understand what happened, and avoid any assumptions since that can lead to incorrect choices being made.

Jan 23, 2026 11:14 AM in response to DavidP225

I would just verify that you are in fact seeing the files on the internal documents folder and just accessing the myDocuments folder on the external drive by mistake.


For instance if you open a file form the external drive the app it opens in, will when saving it default to that location directly.


Also, since Macs don't actually use drive letters like Windows, your external drive will appear as just another location in Finder, with the only indication its external being a small eject icon next to its name. Are you sure you aren't just seeing files on the external drive, because as mentioned macOS will not simply copy files to itself without user intervention.


Perhaps posting a screen shot and redacting any personal or sensitive info, might lets understand what you are seeing.


Jan 27, 2026 1:29 PM in response to etresoft

It's not really paranoia, I don't lie awake at night... but I do remind myself that companies, such as Adobe, who extol the virtues of cloud storage are not primarily looking out for my interests. They just want me to sign up for their next revenue stream.

Keeping away from politics, I am quite surprised by what I have learnt from this thread about possible internal issues relating to cloud storage. The subject never came up in my 'hearing' - there's obviously much still to learn.

There is a button on the Lightroom toolbar to sync to the cloud, so there is obviously a genuine risk of accidental connection. I have therefore uninstalled Lightroom, and after a couple of false starts I managed to install it with default settings, it and its catalogue are where Adobe intended them, and a test shot still found it's way to the desired location on the external drive. All's well so far...

Thanks for the advice - I expect you've saved me from a load of future grief!

Jan 23, 2026 9:00 AM in response to Richard.Taylor

Oops! I've posted my question in the wrong place because I wasn't as alert as I like to think I am... Sorry!

I'll let it stand for a while and hope someone takes pity on me. If that doesn't work out I'll repost it in a more suitable location.

I'm not having any issues in the photographic sphere just now, and my external drive is in APFS format.

I understand that Documents is what would be described as a system folder in PC circles - and not to be messed with. I did manage to Incapacitate a system folder once, and life was very inconvenient for about a year until it suddenly started to function again, which is why I haven't even thought of trying anything clever this time around. I was planning to simply ignore it and arrange for new files to be stored in the external folder, when possible.

Photoshop and Lightroom are in a folder within the Applications folder along with the working catalogue and seem to be working fine. I did this because when first installed to default locations one appeared on it's own and the other appeared within Photos. No idea why that was, it just made me unhappy so I relocated the one that bothered me. Seems fine! Backup catalogue is on the external drive alongside the image files. I don't mind moving files to and fro, as long as Adobe AI functions have enough room, which I'm confident they do.

What is bothering me is the apparent 'Data Grab' by Documents. If it turned out to be almost impossible to divert the output of Pages, for example, that might be inconvenient but not puzzling. It's the copying of a whole file tree from another drive that concerns me - I've always understood that folders were passive repositories, but perhaps this one isn't so passive.

I'm reasonably confident that I haven't done anything to trigger this copying, but no guarantees!

Jan 24, 2026 1:12 AM in response to etresoft

etresoft wrote:

DavidP225 wrote:
Photoshop and Lightroom are in a folder within the Applications folder along with the working catalogue and seem to be working fine.

What do you mean by "the working catalogue"? Those are 3rd party apps, do I don't know how they work. But generally speaking, only apps should be inside the Applications folder.


Lightroom has a catalog file that it uses to help keep track of your full-size photos. I believe that it also likes to keep some cache and/or thumbnail files.


For best performance, these files should live on a fast drive – such as an Apple Silicon Mac's internal SSD. Full-size photo files, which aren't accessed nearly as frequently, can go even on a mechanical hard drive.


However, I have never seen a recommendation that you should put your catalog and cache files into the Mac's Applications folder! Some place like the user-level Documents or Pictures folder seems more appropriate, and Adobe's online Help indicates that the default location is a Lightroom subfolder within the Pictures folder.


Adobe Help Center – Optimize Lightroom Performance

Adobe Help Center – Preference file and other file locations | Lightroom Classic

Jan 24, 2026 3:34 PM in response to DavidP225

Well I deleted the unwanted contents of Documents and it hasn't returned while I wasn't looking, which I'm sure surprised no one, and confirms that whatever triggered the copying was something I did. Still no idea what - I was being careful rather than rushing...but part of the answer may lie in the speed with which data can move on this machine. I couldn't have avoided noticing it on my old one as copying 20GB from SSD to main drive would have taken several minutes, with a progress bar plonked in the middle of the screen.

Note to self: Take more care in future!

So as far as I'm concerned my problem has been resolved. Thanks for helping me through a 'newbie flap'!


I decided to bow to convention and relocated my Lightroom Catalogue to the otherwise empty Documents folder. Hope that soothes any ruffled feelings!

Thanks Again.

Jan 26, 2026 10:13 AM in response to DavidP225

DavidP225 wrote:

I decided to bow to convention and relocated my Lightroom Catalogue to the otherwise empty Documents folder. Hope that soothes any ruffled feelings!


I would suggest not storing the Lightroom Catalog in the Documents folder, for the reason etresoft mentions. Should the feature to synchronize the Documents folder to iCloud be turned on – either now or in the future – there could be problems.


Adobe's default of using a Lightroom sub-folder within the local Pictures folder seems reasonable.


Aside: Likewise, you should never try to move any of your Mac's Photos libraries to iCloud Drive, or to folders which are synchronized through iCloud. The correct way to synchronize photos through iCloud is to leave the system Photos library in a local folder (like the Pictures folder), and turn on iCloud Photos.

Jan 27, 2026 6:49 AM in response to DavidP225

DavidP225 wrote:

It could be an age thing, but the merits of storing stuff that is personally important, in a semipublic location over which I have no control but is probably quite visible to assorted evildoers

Oh no. It's definitely an "age thing". I didn't notice that you had taken this turn towards internet "security" paranoia. If you want to absolutely destroy your experience, make sure to load up on a wide array of antivirus, VPNs, network filter, and other security scams. The only way to stay safe from evildoers out in the world is to invite them to live in your house and pay them for the trouble of scamming you.


No. I was simply saying that these self-contained, internal databases for things like Music, Photos, Mail, and (I assume) Lightroom are literally that - databases. If they are under the control of any kind of 3rd party "sync" tool, they will be hopelessly corrupted in no time. That's why such tools have their own sync logic. That's why iCloud Drive doesn't include Photos or Mail. Even Apple can't do this with their own data. They have to keep it separate. You should too.


You never know when, at some point in the future, your hard drive is full and you think you can save some storage by turning on iCloud Drive Desktop and Documents. I guess you'll save some storage that way. You'll be able to delete your Lightroom data if you save it in Documents because it will just be random bits at that point.


Jan 23, 2026 9:28 AM in response to DavidP225

DavidP225 wrote: …What is bothering me is the apparent 'Data Grab' by Documents. If it turned out to be almost impossible to divert the output of Pages, for example, that might be inconvenient but not puzzling. It's the copying of a whole file tree from another drive that concerns me - I've always understood that folders were passive repositories, but perhaps this one isn't so passive.
I'm reasonably confident that I haven't done anything to trigger this copying, but no guarantees!

That would bother any of us! But I've never heard of it happening-- normal files jumping from folder to folder. A person could make macros or shortcuts or scripts to do that, but those aren't on the Mac skulking around waiting for an opportunity to confuse us-- you'd have to intentionally look for one and intimate it. (I'm just thinking of ways it could go-- not likely at all.)


Do you have a cat? I always blame my cat…


I'd say, see if it happens again. But it's not normal.

Jan 23, 2026 10:24 AM in response to Phil0124

Yes, my previous computers have all been Windows machines. I didn't use Migration Assistant precisely because of its inclusivity - although I was very impressed by its existence! I just took the opportunity to do a bit of decluttering and shifted selected data, via data sticks, into a couple of folders I had previously established on my shiny new external drive. Fairly uneventful, especially with the slow speed of writing to those data sticks... and that's it. I didn't try to move any apps or settings.

Looking in Finder, Documents appeared to be populated almost straight away but at the time I assumed it was just another way to view the same files. That was probably rather muddled thinking, but then Windows did afford multiple viewpoints some of the time - and that's my excuse!

I could go along with a suggestion that I inadvertently dragged one folder into another, but then, surely, the second folder would be visible, whereas what I do see is the contents of one folder within the other. To my mind that's a little more complex to do and therefore less likely to be accidental.

Still, if there's nothing complicated going on behind the scenes, I guess I'll have to conclude it was an epic fumble, so I might as well delete the unwanted copies, and as long as they don't reappear...


Thanks for all the help. I am starting to enjoy the Mac experience, but it's still a bit strange in places!

Jan 23, 2026 10:36 AM in response to DavidP225

Can you tell us a bit more about how you placed these files into myDocuments on the external drive?

For example, did you copy them directly onto that drive while it was attached to your previous computer? Did you copy them to a temporary intermediate location like another external drive?

Did you by any chance copy them to the internal drive of the new computer and then drag them from there to myDocuments?

Unwanted copying of data from external to internal memory

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