can't format external hard drive in high sierra

Hi mate

Yeah its stupid really. Apple have removed the actual disk drives from the display. You will see a "View" option - click this and select the option to display the actual drives. Then select the physical drive you want to format and it will work.

Apple are too busy building their palace to get even the basics right these days...

Taylor, did you get it figured out?

When you open disk utility, click the little view button right below the red yellow and green dots top left.

Then select "Show all Devices."

Then click the device, hit erase, choose a name, Mac OS Extended (journaled), GUID Partition Map

Then it will work.

In Disk Utility click View> Show All Devices then select the Disk not the Volume.

I had this issue with my WD Drive, I have tried all options in this thread with no luck. To solve the problem I had to install the WD application which was on the drive (Or available online). After this I was able to format the drive from within the app to Ex-fat, this allowed the drive to remove all the security barriers stopping Disk utility from Formatting the disk. This was the only thing that worked for me so I hope it helps.

ANSWERED: Your Sidebar might already be open, but it's not showing you all volmes. In Disk Utility, upper left. Click "View", change to "show all devices". It will now appear and you can reformat it.

This works!

With this path (View->Show All devices) I was able to format with High Sierra a new external HD. Last time I used an older Mac to do so. Being able to format external HD´s should be a straight forward process, as it used to be, more so when all external HD come perforated for Windows.
The unquestionable fact that there is a bug in the High Sierra OSC and that Apple does not give a **** about this just points to the new careless, arrogant and stubborn attitude of the company. They believe they will survive out of selling 10 € phones at 1000 €, but they should not bet on it.

I am an Apple user since Apple II first came to the market, back @ 1980. I remained a loyal Apple user even through the lowest darkest times of Apple. I was always willing to pay more for a better more reliable machine. Today's Apple computers are becoming, more and more, just an expensive clone of an unreliable Windows machine...

I am seriously considering just assembling a good PC and switching all together to Linux.

It is really sad to see how Apple just does not care about their ground customers.

In Disk Utility, click the Sidebar button and show devices.

Select the Device and try to format that.

To add what Barney-15E stated if still an issue boot using command-R and try again. I've had some success starting from there on some drives for some odd reason.

OK I got it now 🙂
Yes I was trying to format the 'Volume' not the 'Disc' Why in the world would Apple change that? Thx ByronBound

Yep. Once you reveal the actual disks you can format the drive(s) easily.

A thoughtless and pointless change to the Disk Utility UI by Apple which will cause needless frustration.

The new Apple is too much emphasis on design, too little on usability.

You can try to format the volume not the drive to Mac OS Extended Journaled and proceed to format to AFPS. Cheers 🙂

It seems High Sierra was released too early. Perhaps too many Mac techos have been drafted to iOS work and, as evident in other neglected areas of the Mac, it "just doesn't work". I have just nee rrying to help a friend with a Macbook Pro and High Sierra having the same problem.

You will find that you can format the drive in FAT format on a windows machine or you can go to an Apple store and get them to format the drive on a Mac running an earlier operating system (Sierra or before). Mac OS Extended journalled should work fine with High Sierra even if you can't format the disk on your own Mac.

I am thankful I ignored the update prompts which keep appearing ever few days or so and didn't upgrade to High Sierra and I really resent the continued attempts by Apple to force me to upgrade to high sierra. Apple Arrogance is a thing today...

I switched to the Mac in 2002. But my current Macbook & Mac Pro will be my last Macs.

this is really helpful. VinnieVincent. Well done.
i tried to format Ex-fat, first and then, erased as Mac Os Extended ( journaled ). It's fix the formatting problem.
Really thx to u. cheers.🙂🙂🙂

Any format type resulted in the same error: FAT, OS X Extended, AFPS...

Barney-15E has advised that the disks can be made to appear in the window via the View option.

It seems this may just be a UI issue: Apple have removed the disks from the default Disk Utility display in the upgrade from Sierra to High Sierra. I can't imagine why - formatting drives is the only reason I ever use Disk Utility.

You would expect this from Microsoft but not the Apple of old... I sometimes wonder whether anyone at Apple actually uses their own products...

There is no disk in the sidebar in High Sierra - just the volume.

Yes, there isn't a disk in the Sidebar. That's why I suggested you use the Sidebar button to select the option to show the disks in the Sidebar.