High Sierra / External HD Problems

After hours and hours of research and testing I solved this for me.

When I plugged in my external hard drive it showed up in my drive in Disk Utility but it was grayed out.

I could not mount my hard drives and it would not let me repair, erase, nor partition them, an old and a new one.

I decided to click on the view button at the top right corner of my disk utility app and I had "Show Only Volumes" selected. So I clicked on "Show All Devices" and this showed me each device the volumes were on. I could now select my external hard drive and I was able to easily repair, erase, and partition my hard drives when I clicked on the device instead of just the volume.

I hope this helps anyone.

Many thanks Matthew TR! Your advice was spot on.

Key point: My MacBook Pro OS X is High Sierra 10.13.2 which apparently just introduced APFS (Apple File System). When I first attempted to format the external drive (WD Elements 1 TB) using the MBP Disk Utility, an error message "Erase process has Failed" after erasing was almost complete (about an hour).

Doing research on this problem, I found your advice, as well as some articles that clearly stated how to avoid this error. In my initial erase/reformat effort, the default Disk Utility view (upper left corner of MBP Disk Utility) was set to "Show only volumes", and when proceeding to erase, it returned the error message. One article that was very helpful advised in the upper left corner "View" to "Show all devices", NOT just the partition. I selected the entire drive (not indented on Disk Utility) and then selected "Erase". This worked.

Since my MBP is my personal, home computer and my new HDDs will be for my storage only, I choose the APFS for the new external HDDs to run faster. I have another home computer but it also was upgraded to High Sierra 10.13.2, so compatibility with non-High Sierra OS X is avoided.

Many thanks for your advice!

I found a partial solution to my external drives not mounting or showing up in the drive utility program. By starting up in Safe mode (hold down shift key while doing startup or restart), the drives show up on desktop and in drive utility. I was able to use drive utility and it indicated nothing was wrong with either drive. I was able to use the drives and move data I wanted access to onto some non-RAID 4TB drives. Those drives show on desktop with a regular start-up and seem to work fine in High Sierra. I tried turning off all log-in items to eliminate possible conflicts there at startup. It made no difference in getting the large RAID drives to mount with a normal startup.

Any ideas on what else to try would be appreciated.

This helped me

Les K

Matthew T R Nov 19, 2017 5:38 PM in response to Tim Gavin

Level 1 (4 points)

Nov 19, 2017 5:38 PM Re: High Sierra / External HD Problems in response to Tim Gavin

After hours and hours of research and testing I solved this for me.

When I plugged in my external hard drive it showed up in my drive in Disk Utility but it was grayed out.

I could not mount my hard drives and it would not let me repair, erase, nor partition them, an old and a new one.

I decided to click on the view button at the top right corner of my disk utility app and I had "Show Only Volumes" selected. So I clicked on "Show All Devices" and this showed me each device the volumes were on. I could now select my external hard drive and I was able to easily repair, erase, and partition my hard drives when I clicked on the device instead of just the volume.

I hope this helps anyone.

You are right to be concerned but you should be clear on what the issues seem to be. Apple added APFS to High Sierra, very welcome but immature in OS X, but the company has lots of positive experience with APFS in iOS. Apple itself suggests keeping HFS+ on spinning platters and formatting APFS only on flash, and in fact, converts HFS+ to APFS when you download HS bits from the Apple store. HS can see many external devices using USB 3.0 and can boot images from some of them, but not all of them. Case in point: I do a nightly cloned backup with Carbon Copy Cloner (a bit-for-bit copy of my internal drive) to two external USB 3.0 enclosures, an OWC/macsales On-The-Go and a NewerTech RAID 1, both of which have been in use for >5 years with zero problems, both bootable prior to High Sierra but now only the RAID device is bootable. The On-The-Go still makes perfect cloned copies but to boot any device in it when a clone was made, the drive must be installed inside the machine. The RAID cannot be managed in that manner, but fortunately, it is bootable with HS. I clone an SSD running APFS to disks in the On-The-Go and the RAID appliance both formatted HFS+. Files are interchangeable and if I put the disk inside the On-The-Go inside the machine, it boots and runs apps as well as the SSD, but of course, slower. It takes me 21 minutes to swap drives, which is a pain when, if the OS was working correctly, isn't as convenient as holding down the option key. But, I am protected from catastrophic disk failure of the drive inside the machine. All disks eventually fail so a clone makes it possible to almost instantly recover. Why one works and not the other, since both are USB 3.0 compliant and both have worked for years? Different chipsets and firmware and a very flaky release of macOS. Query the web and you will be able to read a host of horror stories about peripherals that worked with OS X before 10.13 but not after. Only Apple can say why some work and others don't.

My opinion is that Apple released HS to a very demanding and inflexible schedule, and as its release date approached, some bugs and some features didn't make the cut. So, they released it anyway and are now dealing with the fallout. Blame others for your mistakes is a too common response to bugs, but in the meantime, work behind the scenes to fix your mess. Discussion on the net seems to expect many of these USB 3.0 problems will be fixed in 10.13.3, which is on 2nd beta. Apple has not announced a release date nor has it listed which bugs will be fixed. You can trust them but your mileage will vary. I worked around my problem and am now waiting for 10.13.3, but I'm not holding my breath, and since with the help of an engineer at Bombich (developer of Carbon Copy Cloner), I can afford to wait without rushing out to buy replacement peripherals. Apple, it's the firmware stupid, and your ability to deal with it, which is flawed in 10.13.2.

Hi

A little late to the party but thought I would post my resolution in case it helped. After jumping through (a lot!) of hoops in order to upgrade to High Sierra I too had a Seagate 1TB external Hard Drive that was not recognised, nor was I able to mount it via Disk Utility. My drive was an older one formatted as Master Boot Record and not guid journaled, in the end I got the latest NTFS for MAC driver via the seagate website (https://www.seagate.com/gb/en/support/software/paragon/), installed that and opened the Paragon NTFS for Mac 15 software and was then able to mount it via that (breathing a huge sigh of relief as it held my iTunes library). After a reboot it is then visible. I will, of course, migrate my library to a external HD formatted to guid partition map when i get time but for now that got me working!

Cheers

Graeme

You may already know this but just in case you don't, it isn't the choice of drive that is critical, it is the enclosure that holds the drive. Most common and most useful is USB 3.0 but HS has mucho issues with USB devices. The enclosure has a controller chip and firmware that manages the disk, and therein lie the HS issues. HS is broken for some and perhaps many USB enclosures, so finding one that works, and works completely, that is, hosts a bootable image is the real issue. Some will allow files to be copied back and forth but won't boot the os image. In shopping for an enclosure, I would challenge the seller to demonstrate or certify his enclosure will boot HS externally. In my case I have an enclosure I can clone to but can't boot from. My short-term solution while waiting for 10.13.3 or beyond is to swap the drive if my internal drive fails. Not as convenient as holding down the option key but it works.

After upgrading to Sierra I got a ton of problems with external hard drives and USB sticks, most likely due to APFS and bugs with backwards compatability. Sometimes the drives show up, other times they don't, or the icon for them is botches and inaccessible, or the information about the drive is completely faulty, and files that show up are still inaccessible through Finder. However: It is completely accessible if you know how to use the OS X Terminal.

This means you basically have to use Unix/Linux commands to access the external drive through /Volumes/[yourDriveName]/. Here are some useful commands to research if you want to manipulate files with Terminal: ls, pwd, cd, cp, mv and rm (the last command deletes files, so treat with care). You can look them up in the terminal by typing man ls, or man pwd, and so on - if you don't want to use Google... Ctrl+Z quits the manual (yes, the actual Ctrl button). Bonus: You can also mount, unmount and run diagnostics on external drives with Terminal.

After running different tests, including Disk Utility, I can only conclude that there is nothing wrong with my external drives. If you have similar problems, the same may prove true for you. H*ll, sometimes even Adobe Bridge is able to copy things to the drive when Finder is not, which is pretty odd. Thus I can only conclude that there is something wrong with either Sierra/High Sierra, or there's something wrong with the new version of Finder. Anyway, when all else fails, Terminal is your friend. (Apple, really, H*ll is just an expression, not a swear word.)

Hello Tim and everyone having this issue,

I just found out that the problem for me was the "NTFS for Mac OS X" which was installed with the update.

Disabling it (System preferences>NTFS for MAC OS X>Turn the Paragon...) allowed the disk to be accessed properly.

Hope it helps you guys.

Hi,

I purchased a 4 TB Western Digital external drive today to back up my iMac 27" which have High Sierra. Lucky that I saved the files before I allowed the iMac to format the 4TB drive. It displayed an error and after that the drive is inaccessible. I took the 4TB to my PC and was able to reformat the drive and keep trying 3 more times with the same issue.

What fixed it for me is that when the 4TB is connected to the Disk Utility, it would show the drive as grayed out so you would not be able to format or mount. I noticed that there is a "View" menu and that it was displaying "View all volumes", change that to "View all drives". After that select the 4TB drive and was able to format it by giving it a name and use Mac OSX Journal, which was what my Mac Hard Drive was using. After format, the drive works and was able to use Time Machine.

This fixed my issue and hope this help other people.

I went to an older iMac still running Sierra, & used Disk Utility. Once I'd formatted the drive on that system, I could use it on High Sierra.

This happened to me as well, and I spent hours on the phone w/support. There was nothing I could do to fix any of the drives that appeared to be going bad - on a Mac. However, I was able to recover them simply by accessing the files on a PC... then the drives started working ok again in High Sierra.

(that said, I am still troubleshooting why my computers come to an unbearably slow speed when the drives are plugged in.)

I’ve been having the same exact issue. Spent a long time on the phone with Apple through diff calls, they continue to deny that this issue exists or that it is even in the forums.

The only thing I could do is making an OS Sierra boot drive, format the internal, reinstalling OS Sierra and use my latest Os Sierra time machine backup for a restore.

Annoying as ****!

So, after testing my drives on a friend's two i Macs with High Sierra installed and experiencing the same issues I eventually got tired of fighting with the High Sierra OS and did a clean install of El Capitan. All my drives are running smoothly again and I am able to transfer files effortlessly. Drastic times call for drastic measures,

Hi shnyhd, read my post above. You may have the same issues as I did. Before you restore your system, sort out your time machine first.

Unlink your backup from your system, make sure you remove all rules as well including removing any folders excluded from your back ups. Once you have it complete unlinked from your mac, erase your backup file from the time capsule. When that is done you can again set up your time machine as before and do your first back up.

After your backup is done you can move on to investigating your external drive. In my case the time machine was causing conflicts in disk utility with seemed to freeze out any other external drives. Once my time machine was sorted, everything went back to normal.