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Andre John Mas Author

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

ssspol

Level 1

9 points

Posted on Dec 18, 2017 7:01 PM

I don't believe it has anything to do with USB. It doesn't work for me when using both USB and Thunderbolt. After some digging, I think it all has to do with High Sierra and APFS. High Sierra is deemed one of the worst OSX updates in Apple's history and it could be simply just a lack of support for spinning HDD drives and that's why nothing will mount. Unfortunately, that makes this a waiting game for an update to fix all of this due to Apple leaving HFS+ and going to APFS.

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59 replies

mpickar

Level 1

4 points

Jul 7, 2018 7:42 PM in response to Andre John Mas

I have found the steps given in the link below have resolved issues a few times now when I run into a disk that fails to mount in High Sierra.

https://mycyberuniverse.com/web/how-fix-mediakit-reports-not-enough-space-on-dev ice.html

First time I ran into this issue, it was with a brand new WD Elements HD. I think I eventually found the correct information on Western Digital's website, (which is referenced in the link provided). I ran into this issue again this evening with an old APPLE (Maxtor) hard drive from an old eMac... Seriously Apple - fix your tools... one shouldn't have to find "obscure" terminal commands to do something that DiskUtil should be addressing, particularly if erasing or reformatting a drive... Note that this fix is one to try after other steps (restarting, single user mode disk check, etc.) if the drive has data on it that you need. In my case, I was not concerned with retaining any data from the disks involved.

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.

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.