Seagate External Drive will NOT erase and is now invisible in Finder

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Seagate External Drive will NOT erase and is now invisible in Finder

Running 10.11.6 on an iMac and am trying to format a 2Tb Seagate Expansion Drive to use to instal a back up operating system. Have done this many times before. However this time I connected the brand new drive, opened Disk Utilities and went through the process of erasing to an Apple format and the operation failed due to

"MediaKit reports not enough space on device for requested operation. Operation failed..."

The disk is now invisible to my desktop despite disconnecting and reconnecting the disk and also restarting the iMac. I have run DiskTools which is unable to see it and DiskWarrior which can see the disk but sees it as two partitions and unusable. I have tried mounting it through DiskWarrior but failed.

The disk was brand new and arrived today from Amazon.

I really need to start a back up tonight and was wondering if there was a simple way around this problem

Many thanks

Posted on Jun 24, 2017 4:40 PM

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Answer 1

Geggsy125 Author

Level 1

10 points

Jul 4, 2017 1:11 PM in response to Aroundsp

Really sorry to hear you're having that problem. It is very frustrating.

I had Disk Utility open and chose the Partition tab (NOT the Erase tab). This started the procedure but then brought up an alert/warning that it couldn't be completed because of Journaling (I think there was an issue because the partition that was visible was a Windows Partition). If I tried to Journal it then I was getting an error. I kept trying and at one point I noticed that there seemed to be partitions being created. This is when I then went down the creating one large partition and followed on with the erase.

This was a hit and miss, try and strike lucky sort of procedure. I am not skilled with computers. The above is very simplified as I was hacking at it for a good couple of hours (but that does include before I sussed the Partition issue). During that time I would periodically restart the Mac. I did at one stage try to do it through the Terminal but was getting the same error message.

Each time the Mac started back up I was getting this message:

When I was trying to erase I was getting this message:

This was (I think) because that Windows partition was only a couple of Mb so wasn't enough space for the Finder files Apple has to have on there.

The next image shows the way the Finder was looking at the disk:

The "Seagate El Capitan 2017" dos is the one running my iMac (the internal drive died years ago). You can see the "Unknown Disk" and the "Basic data partition" are the 2 partitions on the one disk which is where the problem lay. This is what made me start thinking it was a partition problem.

This is an image from Diskwarrior which I tried to use to see if it could do something:

As you can see it says that the file system is unsupported

The Windows partition is on there because Seagate want the drive to be used by both Mac and PC out of the box. I wish they wouldn't do it as we are mostly used to reformatting drives when we have them.

Sorry I can't be more helpful but I am hoping something here may jog it along for you. Also would be worth trying Google with specific terms and dialogue from the above images. That may yield better results from someone who knows more about what they are doing.

As a side note, I am about to go to bed so if you do write I won't see it till morning. I hope this works for you and would love to hear how you get on. Best wishes

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Answer 2

Dec 17, 2017 7:01 AM in response to Geggsy125

First you wanna identify the name of the disk. You know how to do this. Open Terminal and type:

diskutil list

Rad!
Look for that external hard drive or USB drive that is being a jerk. Find out if it's disk2, disk3, or whatever.
Next, you gotta get this disk to UNMOUNT. Let's enter this next line into Terminal;

diskutil unmountDisk force disk2

Of course, “disk2” is what the name of MY current device is, but it may be different for you. Check that ‘diskutil list’ list.
However, for now, you should be seeing
“Forced unmount of all volumes on disk2 was successful”
That’s how ya know ya done did it!
*Spoken with a southern twang*

Next, we need to remind this disk who we are, and not to f**kin play games with us! We are the bosses here! This ain't Terminator 2, Judgment Day (yet)!
We ‘bout to write zero’s to this disk, and nuke this b**ch!
(Translation: We are zeroing out the data on the disk.)

sudo dd if=/dev/zero of=/dev/rdisk2 bs=1024 count=1024

Hey!
Do not forget to replace the rdisk2 before pressing the Enter.
Then enter your password when asked to.
You’ll see something close to this when done:
Password:

1024+0 records in

1024+0 records out

1048576 bytes transferred in 0.890086 secs (1178062 bytes/sec)
Dawg,

You’re going to Hollywood!
We are almost there.
For this next step; Remember to change ‘disk2’ to what ever you have as a name for your disk. AND! we need to change “MediaDrive” to what ever name you want your drive to have.
Let’s now try to partition the disk. This will be the HFS+ format:

diskutil partitionDisk disk2 GPT JHFS+ “MediaDrive” 0g

Hooray!!! The Disaster is over!
But don’t forget to change from HFS+ format to APFS format using Disk Utility, bruh!

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Answer 3

Geggsy125 Author

Level 1

10 points

Jun 25, 2017 3:44 AM in response to Geggsy125

I think I've solved the issue. So for anyone who may be facing a similar problem here goes...

I feel that the issue was with the partition that was placed onto the drive by Seagate for Windows users. The drive was primarily marketed at Windows but is good for both. The Windows portions was a separate partition but very small (135Mb on a 2Tb drive).

I messed around in Disk Utilities with the partitioning (it didn't like that as it couldn't find the journaling) by adjusting the choice of format. Eventually it recognised the structure and allowed a partition, 3 in total. I was then able to erase the disk. I then erased a second time but that time I renamed the disk.

So far so good... Was able to create a clone using CCC onto the disk. Clone went ok but I haven't tried starting from it yet

Hope this helps even though a bit vague but I am really tired now 🙂

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Answer 4

Geggsy125 Author

Level 1

10 points

Jun 26, 2017 9:02 AM in response to kahjot

Thanks kahjot. Even though I've gone through the procedure over a hundred times over the years I will definitely take note of your suggestion. Better to do it at the start when the drive is responsive that try to tweak it when it's appearing half dead.

Thanks again

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Answer 5

lischmit

Level 1

4 points

Mar 11, 2018 6:17 AM in response to Beezermigs

I had the problem too, for Seagate 5Tb, did help be to use the step by step procedure with small change :sudo dd if=/dev/zero of=/dev/rdisk2 bs=5120 count=5120! It worked, after may days of searching for the solution this was the only one working! THANK YOU

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Answer 6

ladnan

Level 1

4 points

Mar 29, 2018 1:24 PM in response to Beezermigs

Ive done it all so far and it seems to be working well, but when i get to the password stage instead of what you wrote:

You’ll see something close to this when done:
Password:

1024+0 records in

1024+0 records out

1048576 bytes transferred in 0.890086 secs (1178062 bytes/sec)

It instead says:

Password: "and has a symbol of a key here"

and it doesn't let me type anything afterwards

Id appreciate it if you could help, because i have no idea how to fix it

Thanks!

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Answer 7

Apr 1, 2018 6:12 PM in response to Geggsy125

I used the following to format my 8TB Seagate drive. My drive, although it mounted at first, when I tried to erase it using Disk Utility, it failed and then no longer would mount at all. I opened Terminal and issued the "diskutil list" command and saw (also noted from research online) that it had a Microsoft Reserved partition which is what causes it to fail to erase using Disk Utility:

/dev/disk3 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *8.0 TB disk3

1: Microsoft Reserved 134.2 MB disk3s1

2: Apple_HFS 8.0 TB disk3s2

I issued the following command and it erased and mounted and was erasable in Disk Utility:

diskutil partitionDisk /dev/disk3 1 GPT HFS+ newdisk R

-Scott

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Answer 8

kahjot

Level 4

2,463 points

Jun 25, 2017 7:55 AM in response to Geggsy125

When you originally tried to format the drive, did you choose Erase or Partition?

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Answer 9

Geggsy125 Author

Level 1

10 points

Jun 26, 2017 2:21 AM in response to kahjot

I went straight to erase as I didn't need what they had on the disc. It was the third disc I had done that evening and the others were ok. I've done it loads of times before never had an issue

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Answer 10

kahjot

Level 4

2,463 points

Jun 26, 2017 8:08 AM in response to Geggsy125

Safer to go to directly to Partition. You can effectively erase by resetting your volume to one partition.

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Answer 11

Aroundsp

Level 1

4 points

Jul 4, 2017 7:43 AM in response to Geggsy125

Hi!
I'm having the same problem and now my mac doesn't see the drive anymore, is "half dead" as yours.. how did you made it visible again?

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Answer 12

Aroundsp

Level 1

4 points

Jul 5, 2017 8:37 AM in response to Geggsy125

Thank you so much for your attention!
I was trying to help a friend, but he decided to take the drive and change it for a drive to mac. He didn't notice that when he bought it..

Best regards!

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