Large file copy to external disk fails

Question

Large file copy to external disk fails

I am trying to copy a very large file (a photolibrary file) to an external disk, in a desperate attempt to rescue photos on my lap top that has been ongoing for a couple of months now. The copy starts OK and proceeds for about an hour or so, then fails, telling me that a file of that name already exists. In fact, the file that exists is the file that finder has created. I delete the file, empty bin, start again, same problem. From what I can see, finder seems to be getting its knickers in a twist thinking the file it has just created, and SHOULD BE continuing to create, "already exists" and is the problem. Has anyone else seen this, and is there anything I can do?

Posted on Nov 11, 2024 2:59 PM

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Answer 1

MartinR

Level 7

21,685 points

Nov 11, 2024 7:00 PM in response to seanfromminato-ku

How large is the photolibrary file? What is the external disk (make & model), what is its format and how is it connected to your Mac? Are there any other devices also connected to your Mac?

If the connection is USB, are you using a USB hub? (If you are using a USB hub, try connecting your drive directly to your Mac without the hub.)

Are you currently able to use this photolibrary or is it corrupt and unable to be used by the Photos app? Reason for asking ... if you can open & use this photo library, for "rescuing" your photos, I suggest exporting all the photos to a folder on your Mac. You might also want export just a portion at a time rather than the entire library all at once.

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Answer 2

Nov 11, 2024 8:25 PM in response to seanfromminato-ku

This is the system message I get. Obviously there is actually no such file when the copy starts, when it appears to run normally for about 10 minutes or more, then this error appears:

So it kind of appears as if it is complaining about itself, and what is has just done/is in the process of doing.

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Answer 3

Nov 11, 2024 9:18 PM in response to MartinR

Files is about 307 GB

Disk is WD elements 10B8 media, format is Mac OS Extended (Journaled), connected directly to iMac. Other device are connected.

This library can be used and is the system library for this iMac. I am trying to make a copy so that I can then use that copy as the system library on another computer.

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Answer 4

Nov 12, 2024 12:08 AM in response to seanfromminato-ku

Make sure the source and target drive are both formatted as case-insensitive (APFS or MacOS Extended (GUID)) because otherwise there might well be a filename clash.

Photos library is not a file but a folder disguised as a package. It has numerous tiny-large files. Sometimes the Finder copy might have trouble copying them so some users have opted to open the package (risky!) and copy files in smaller chunks via the Finder. A better option is to clone the library folder to the target disk folder with Carbon Copy Cloner.

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Answer 5

Nov 12, 2024 4:28 PM in response to ActualHelp

That won't work though as it is a package that I can't really dissect and put back together again. I have given up on this attempt to fix my photos. The fact that finder gives an error that a file already exists, when clearly the file that exists is the file it is on the process of making is , to me, a clear OS anomaly. I appreciate all the helpful advice but I have no interest in jumping through hoops because the OS won't do its job. What now "appears" to be working is taking this external back to the original computer, creating a new library, making that the system library, and turning on iCloud sync. It seems to be progressing but looks like it might take about 2 Millenia to download all the images. Thanks again for the suggested fixes, they all made sense.

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Answer 6

Old Toad

Level 10

210,597 points

Nov 12, 2024 1:51 PM in response to seanfromminato-ku

How is the drive formatted?

Create a folder on the EHD and try copying the library to the folder.

If that fails the using the demo version of Carbon Copy Cloner to clone the library to the EHD.

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Answer 7

Nov 11, 2024 10:54 PM in response to seanfromminato-ku

I get this kind of junk when attempting to move large files all at once.

What worked for me was copying smaller folders at a time to the new location, even though it's a time-consuming pain to do.

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