Trying to open a file on one volume, opens the same file on backup volume instead!

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MacTitan Author

Level 1

19 points

Trying to open a file on one volume, opens the same file on backup volume instead!

Just upgraded from Yosemite to El Capitan.

Running a Mid-2011 27" iMac, 3.1 GHz Intel Core i5.

Running OS from 1 TB internal hard drive (mechanical), with home folder on external drive.

Two external Stardom dual-drive enclosures, one FireWire and one USB 2.

The FireWire enclosure contains the disks "Data" and "Media", while the USB 2 enclosure contains "Backup Data" and "Backup Media".

I'm experiencing a problem I've never seen or heard of before:

If I try to open a file on one of my main disks, e.g. the volume "Data", it seems to do so.

However, what it actually does, is open the backup of the same file on the volume "Backup Data".

For years, I've relocated my home folder to external, larger drives.

I've pointed my home folder to /Users/perData, which is a symbolic link to the external /Volumes/Data/Users/per.

("Data" being an 2 TB disk).

(I previously used to point the home folder directly to the folder on the external FireWire drive, but every so often,

a delay in the mounitng of that disk lead to a "ghost" volume "Data" being created on the internal drive, and the real Data

ending up as "/Volumes/Data 1")

I haven't experienced this behavior in any previous version of Mac OS X.

The only thing I did different from previous OS installs, is that I let the install use use my full "FirstNameLastName" to name my home folder.

In this case, I'm now pointing my home folder to "FirstName" instead of "FirstNameLastName" on the system volume.

Never heard of any problems related to pointing to a folder that's not named the same.

My current user has the same ID (501, user name "FirstName LastName") as the one I used before I upgraded (501, user name "FirstName").

I suddenly discovered the anomaly, when dragging the folder "Favorites" down into the dock, and it appeared as the same, older version of the folder

from the backup drive. The new one had just two folders in it. The old one - which appeared in the Dock, had plenty.

Every single file I've tried to open from my regular home area (on "Data"), instead opens up the same file on "Backup Data".

It works the same in terminal as well as in Finder:

if I do "open "/Volumes/Data/.../Somefile.txt", what's opened is "/Volumes/Backup Data/.../Somefile.txt".

Doing "open "/Volumes/Backup Data/.../Somefile.txt" does indeed open the file from the "Backup Data" volume.

ONLY the files that happen to be unique (new file that doesn't yet exist on the backup volume) are opened from the "Data" volume.

Saving files works - They end up where I save them, and not on the wrong volumes.

If I Command-click on the title of a document, I can successfully select the folder the file resides in, and it opens in Finder.

The same thing happens trying to open files on the volume "Media", which instead opens the same file on the volume "Backup Media".

Chang ing the name of the backup volumes made no difference - it's not some weird "names pretty similar" bug. If the file is there, in the same location, it will open instead of the file I'm trying to open.

If I use Disk Utility on the "Data" or "Media" volumes, what happens is that now THEY work, but when I try to open files from the backup volume, then the file on the main volume opens up. After a repair of "Data", "open "/Volumes/Backup Data/.../Somefile.txt" will open /Volumes/Data/.../Somefile.txt.

So - it's a one-way "mistake", whose direction is reversed whenever the previously "unopenable" volume is "repaired" in Disk Utility.

I've tried to rebuild indexes, but has had no immediate success - Never seen this problem before on any computer or any version of Mac OS X.

I've also noticed that most files give me a warning that I can't open them, because I don't have the right permissions. The Finder Info-window show me that I have read and write access to it. A second attempt opens the file. File info doesn't seem to indicate a "sudden change" between attempts. Never seen this behavior either.

Anyone have any idea what's causing this?

iMac, OS X El Capitan (10.11.3), 27" Mid 2011, 3.1 GHz Intel Core i5

Posted on Feb 28, 2016 8:20 PM

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Answer 1

MacTitan Author

Level 1

19 points

Feb 29, 2016 6:37 PM in response to MacTitan

Update:

Since I had a suspicion something had gone South when installing El Capitan, I cleaned the System disk and reinstalled Mac OS X.

What's interesting, is what I did during that install. I decided to hook my external Stardom enclosures up to my brand, spanking new MacBook Pro 15". New computer, same OS - factory installed. USB enclosure connected through a 2.0 hub (enclosure isn't 3.0 anyway), and the FireWire enclosure connected through the Apple ThunderBolt adapter.

MacBook Pro Retina 15", Mid-2015. 2.5 GHz i7, 16 GB, 500 GB storage, AMD Radeon R9 M370X. El Capitan, 10.11.3 (same OS version as the iMac).

Guess what? The same thing happens here. Opening a file on /Volumes/Data opens the same file on /Volumes/Backup Data instead. It is NOT a wonky OS install on my iMac, it seems. El Capitan just seems incapable of the most basic task of actually knowing what lies where.

I'm thinking some deep level bug here - something Apple hasn't actually tested, because everyone's running 1 single disk, right?

I couldn't help but notice that my drives got sorted differently on my desktop after installing El Capitan on my iMac. Weird, I thought to myself - Sorting by type has never looked like this.

For some reason, it seems like disks in the Stardom USB enclosure is regarded as "Internal" now, while FireWire drives remain "External". It's not all USB devices - a Kingston USB stick remains "External":

It's almost as if the OS thinks "Oh! Nice! A file on an external volume. But I seem to have the same file over here - on an internal volume. Much better. I'll open that one instead!".

I decided to make a 100 MB disk image, and duplicate it, making sure to setting the duplicate's volume name differently:

I made sure I had the same content in both volumes:

Now for the interesting part: Would the files open from the wrong volume?

YES. They do. This is clearly not something to do with USB or FireWire, or "internal vs external". I started out with a fresh disk image, duplicated it, renamed the file and the volume, created three folders with three files in them on Disk1, and copied them to Disk2. Just as a backup using e.g. FoldersSynchronizer (my current backup program) would do.

Here's what happened:

So far, so good, right?

Wrong:

So - While the files I tried to open from "Backup Data" worked as they should, and the files from "Data" got "picked" from "Backup Data", in this case it's Disk1 that works, and anything from Disk2 is opened from Disk1.

What if the files have different content? I added " on Disk1" only to ThisIsTheFirstFile.txt on Disk1, and tried again.

The files have different modify dates, and different content. ONLY if the names and/or locations are different, will the correct file open. When I press space, the previews are correct - Showing the contents of the actual file on the correct volume I'm actually dealing with.

It makes no difference if I double-click on a file or use "open" in Terminal - the wrong files gets picked.

I can open files from within the programs, and the right one gets picked.

I can also save from within the programs, and the file goes where I'm telling it to.

The rest can't be anything but a bug.

Could anyone else try the same experiment with two identical Disk Images and see what happens?

I'm using a Norwegian setup with Norwegian OS, keyboard, etc., but that shouldn't have anything to do with it.

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