Level 4

1,083 points

External hard drive won't mount in high sierra

Is something broken in High Sierra when it comes to external USB HDs? Did something break in the USB stack?

Up until installing High Sierra I have been able to mount my external USB hard-drive with my MacBook Air. I now try connecting it and it will not longer mount. It isn't even listed in the USB devices section, when I check "System Information".

Originally I thought the drive was broken, but I did some digging and none of my Seagate drives will mount. Same issue with all of them (I have three Seagate drives: 2 FreeAgent GoFlex and 1 Backup Plus Portable Drive). They don't appear in the list of USB devices and no LED activity of the drives. They are all USB 3.0 based drives.

They all work on my old Mac Mini, which is running macOS 10.11.6. Two of the drives are HFS+ and the other is NTFS.

An older USB 2.0 based drive mount fine.

I am using macOS 10.13.1 on the MacBook Air.

MacBook Air, macOS High Sierra (10.13.1), null

Posted on Nov 12, 2017 8:07 AM

Top-ranking reply

tbirdvet

Level 6

17,108 points

Posted on Nov 12, 2017 2:21 PM

Had similar issue. Open disk utilities. If none of these drives show up look for the menu (new in High Sierra) that states "show all". If drive shows up try repair and if that does not work you may need to reformat it if nothing on that needs saving. I had two drives that I needed to fix that way. They were both fine with Sierra but High Sierra must be doing something different.

View in context

59 replies

Jan 1, 2018 4:02 AM in response to mrmcsmitty

Yep tried that, view all didn't show any extra drives

BRN2SHN

Level 1

9 points

Jan 1, 2018 4:19 AM in response to Mashoo811

Go to System Preferences> Spotlight> Deselect all in list, then plug in your external HDs. Once each is recognized you can set Spotlight to default preferences.

Bru2060

Level 1

4 points

Jan 1, 2018 10:47 AM in response to BRN2SHN

Worked for me.

Thanks!

Jan 1, 2018 10:59 AM in response to Tim Castleman

Update - the drive is recognized in Disk Utility, but the data file is grayed and it doesn't appear in Finder. This drive worked on this machine at one time, I don't know how many updates ago.

Csound1

Level 9

60,063 points

Jan 1, 2018 11:01 AM in response to TonyBrVa

So, just you then.

Jan 1, 2018 11:03 AM in response to Csound1

Wow - SO Helpful! Happy New Year

Csound1

Level 9

60,063 points

Jan 1, 2018 11:05 AM in response to Tim Castleman

And to you.

Jan 1, 2018 8:47 PM in response to mrmcsmitty

Thank!

vilko

Level 1

6 points

Jan 4, 2018 3:30 AM in response to Tim Castleman

Mine is not listed in Disk Utility, not even when show all selected. I have 5 years worth of backups on that disc.

BRN2SHN

Level 1

9 points

Jan 4, 2018 6:00 AM in response to vilko

Find and try what is in my post

Jan 21, 2018 5:13 AM in response to mrmcsmitty

Doesn't reformatting mean you lose all your files???

Csound1

Level 9

60,063 points

Jan 21, 2018 5:41 AM in response to SpiralDreamer

SpiralDreamer wrote:

Doesn't reformatting mean you lose all your files???

Yes it does, unless you have a backup

Jan 25, 2018 9:46 AM in response to tbirdvet

Thank you so much!! I had spent hours troubleshooting a brand new Western Digital Elements hard drive. As soon as I did this, the OS had no problem formatting to Mac OS Extended. You rock!

ioscev

Level 1

8 points

Mar 3, 2018 2:54 PM in response to Al_J_H

Same problem here.

NYCMoi

Level 1

8 points

Mar 6, 2018 3:29 PM in response to MasterNater

Which thing did you do that actually worked, please? Getting desperate over here!

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External hard drive won't mount in high sierra