Want to image Wininstall BootCamp USB Drive

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Level 1

11 points

Want to image Wininstall BootCamp USB Drive

I recently used the Bootcamp Assistant (in El Capitan, 10.11.5) to create a Windows 10 bootable USB and install Windows 10 on my Mid-2012 Unibody MacBook Pro (15", not Retina display). Installing Windows 10 using only the Windows 10 ISO did not appear to be an option available to me.

I used my 32 GB Sandisk Extreme drive, and I'd like to make a functional image of it, preferably an ISO, but not necessarily, and free up my USB drive for general use. Since my laptop has an optical drive, I wouldn't mind being able to burn that image to a dual-layer DVD.

I know that Disk Utility can make an image of the USB disk. What I don't know is whether I can create a bootable USB or DVD using that image in the future.

Has anyone tried doing this with success? All the tutorials I can find for Boot Camp discuss how to create the USB installer starting with Microsoft's ISO. Nothing I've found talks about going the other way. I've seen some tutorials for USB to bootable ISO using ImgBurn (Windows), but they generally say they probably don't work for EFI booting.

Thanks for looking

MacBook Pro (15-inch Mid 2012), OS X El Capitan (10.11.5)

Posted on Jul 28, 2016 7:32 AM

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Answer 1

Loner T

Level 9

59,471 points

Jul 28, 2016 7:35 AM in response to gh1852

You can use OSX Terminal dd command to create an image and preserve the boot ability of the USB image. DU will create a DMG which you can later restore to a USB, but to make it bootable requires GPT Fdisk and marking the MBR as Bootable. On 2015 and later Macs, there is no USB Installer facility.

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Answer 2

gh1852 Author

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11 points

Jul 28, 2016 8:34 AM in response to Loner T

Am I not correct though in assuming that dd will create an img file that is roughly 32 GB in size if my USB drive is 32 GB?

I'd love to have a 6.8 GB ISO or other image format that I could burn to a DVD. Perhaps that is something that's going to be not worth the effort.

I know that you can ask dd to gzip the img to save storage space.

Thanks

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Answer 3

Loner T

Level 9

59,471 points

Jul 28, 2016 10:38 AM in response to gh1852

The dd output will be the same size. Gzip will compress it. The challenge with the ISO/DVD is that it will not boot from the dd image. It also requires an Apple Superdrive to be tested.

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Answer 4

gh1852 Author

Level 1

11 points

Jul 30, 2016 7:32 AM in response to Loner T

My MacBook Pro (unibody) has an internal optical drive. However, I ran into a more annoying issue with dd. After creating about 2/3 of the disk image, it stopped, and in Terminal, said that the "Device is not configured".

So I have a dd image, but I'm also sure that it's not of any use for the future, as there are about 12 missing gigabytes. I did a lot of searching for what Device not configured could mean or what to do about it, but couldn't find any one thing to look for.

I did run a utility for Windows called USBImage that successfully imaged the whole thing, including doing SHA-1 and MD5 checks to verify the image vs. the drive. But to use that image, I have to have access to Windows. I'd prefer having something that OS X can use to recreate the flash drive.

Thanks

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Answer 5

Loner T

Level 9

59,471 points

Jul 30, 2016 7:45 AM in response to gh1852

gh1852 wrote:

My MacBook Pro (unibody) has an internal optical drive. However, I ran into a more annoying issue with dd. After creating about 2/3 of the disk image, it stopped, and in Terminal, said that the "Device is not configured".

So I have a dd image, but I'm also sure that it's not of any use for the future, as there are about 12 missing gigabytes. I did a lot of searching for what Device not configured could mean or what to do about it, but couldn't find any one thing to look for.

The dd command can be run again. Before you try again, can you post the output of diskutil list after your USB is connected as well as the dd command line? The partial dd image is not going to work. Another option is to use CloneZilla.

You can also create a DMG, wipe the USB, restore the DMG and test for boot ability.

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Answer 6

gh1852 Author

Level 1

11 points

Aug 2, 2016 5:02 AM in response to Loner T

Thanks for your response. I had been using the correct disk designation from diskutil list before, but for whatever reason, it wrote about 20 GB and gave the "Device is not configured" error. I did a fair amount of searching for dealing with that, and saw a few mentions of using dd as follows - dd if=dev/rdisk 1 of= etc. instead of dd if=dev/disk1 (or disk 2, or whatever). I tried it and I got the whole flash drive imaged and was able to successfully use dd to restore it and have the flash drive be bootable.

I wish (now) that during the imaging of flash drive, I had used the bs=1m option. I did that when writing the image to the flash drive and it must have been 100 times as fast.

Thanks

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Answer 7

Loner T

Level 9

59,471 points

Jul 31, 2016 5:31 PM in response to gh1852

Usually the raw disk (rdisk - character device ) is used, instead of block disk for dd.

ls -lgd /dev/rdisk0

crw-r----- 1 operator 1, 0 Jul 31 07:10 /dev/rdisk0

ls -lgd /dev/disk0

brw-r----- 1 operator 1, 0 Jul 31 07:10 /dev/disk0

Good to see it working. 🙂

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