Time Machine error 2 HD disks with the same name

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Time Machine error 2 HD disks with the same name

Time Machine fails to back up. OS is High Sierra. Error messages says there are 2 disks with the same name. If you go to disk doctor you find the Macintosh HD and Macintosh HD Data only, but if you go to Time Machine preferences you see that disks appear duplicate. (See screen shot). Haven't been able to find on the web any answer to this. Onyx, Disk Warrior also see only one disk. There is no "delete" from the Time Machine preference window. How do I correct this? Thks

MacBook Air 13", macOS 10.13

Posted on Apr 11, 2020 2:11 PM

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Answer 1

Top-ranking reply

alanfromberkeley Author

Level 1

8 points

Apr 29, 2020 8:59 AM in response to Jeffc98

Jeff you are exactly right.

However, I found an easier more permanent solution: to plug in the Apple USB-C Digital AV Multiport Adapter I use to connect the PB to the USB hub. When the PB went to sleep the hub lost power and caused the disconnection and then creation of multiple phantom disks.

Ultimately what worked for me was simpler. After I plugged the adapter I re-started the computer. That erased all the phantom disks automatically and then with the adapter connected, the disks don't eject at sleep anymore.

Easy when you know the answer....

A

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Answer 2

Jeffc98

Level 1

8 points

Apr 29, 2020 8:47 AM in response to alanfromberkeley

I had the same issue. I finally got it resolved today (without reformatting the time machine drive or reinstalling MacOS); this is what worked for me:

The "disks with the same name" were phantom volumes of my external backup drive. As in alanfromberkeley's case, they showed the name "Macintosh HD" but when hovering over them, they were actually copies of the external drive. ("External HD 1", "External HD 2" etc.) They did not appear anywhere else in Finder or disk utility; only in Time machine.
I was able to delete the phantom volumes by following the steps in the superuser thread listed below. The short version is this:
1. Make sure all external disks are physically disconnected.
2. Open a terminal window.
3. type: cd /Volumes
4. type: ls -la
5. This should show the phantom volumes in addition to a link to the real Macintosh HD ("Macintosh HD -> /")
6. For each of the phantom drives, type: sudo rmdir "<drive name>" (where <drive name> is the name of the phantom volume, e.g. "External HD 1". You need the quotes so terminal will see the spaces as part of the name)
7. You will be prompted for your password the first time you use a sudo command.
8. Restart your computer
After this, Time Machine worked for me again. I suspect the reason this happened in my case was that I have my external drive attached to my Macbook through a docking station, so I didn't always eject it before unplugging my Mac or putting it to sleep. The phantom volumes apparently are created when Mac OS tries to write to a disconnected disk.

Reference:

https://superuser.com/questions/20879/how-to-remove-duplicate-ghost-network-drive-on-os-x

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Answer 3

Apr 11, 2020 2:34 PM in response to alanfromberkeley

SOLVED

What likely caused the issue: After system update Time Machine did not recognize the old backups on the disk. A screen appeared asking to replace the disk or use "both". Probably selected "use both" and inadvertently created two backups. The error message said there where 2 HD disks, when they were 2 backup logs.

How I solved it: Formatted the backup disk and renamed it differently. When promoted by Time Machine I chose "replace disk" instead of use "both" Lost all previous backups but I have one now.

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Answer 4

Apr 11, 2020 2:19 PM in response to alanfromberkeley

If you hoover over the disks, the first one is the actual Mac HD, but the second appears to be inside the Time Machine Backup Disk. Volumes/RedSeagateTimeMachine_1

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