I have a very complicated and time consuming Windows 10 install on my mid 2018 Macbook Pro (running 10.14.6 Mojave) Bootcamp partition. Virtualization (including Parallels 15 with Metal support) is not an option as this install is for Oculus Rift development which requires a very specific driver setup and as much video memory as possible from my eGPU.
I am also using Parallels 15 to run from the bootcamp partition when I'm in Mac OSX and I don't need to run the Oculus (again the drivers are different for display so this is useful to modify files, or do development when I do not need to run the Oculus). I only mention this as maybe there is something Parallels does to the partition that confuses Disk Utility?
I would like to create a backup of the bootcamp partition in order to restore later if needed. I have seen several people use Winclone, SuperDuper as well as vanilla Disk Utility with dd and hdiutil. I would prefer not installing any external software as I know this should be totally possible with the already installed software.
When I follow the instructions online here. The first step is to simply create a dmg image of the bootcamp partition with Disk Utility by right clicking on the Bootcamp partition and selecting
Image from ... where '...' is the name of my Bootcamp partition. I leave
none. When I hit save it unmounts the partition and gives me an alert to grant permission for the operation:
diskimages-helper wants to make changes. Touch ID or enter your password to allow this.
I would prefer to grant Disk Utility and any helpers permissions so I don't have to allow every time as I'm curious if this is part of the problem. Once I do grant permission Disk Utility continues with creating the disk and reports that is was successful.
here is the detailed output:
Creating disk image from “BOOTCAMP” (disk0s3) Unmounting “BOOTCAMP” Preparing imaging engine… Reading Master Boot Record (MBR : 0)… (CRC32 $90E6AEF8: Master Boot Record (MBR : 0)) Reading (Apple_Free : 1)… (CRC32 $00000000: (Apple_Free : 1)) Reading (Type 72 : 2)… (CRC32 $6B3CCE6A: (Type 72 : 2)) Reading (Apple_Free : 3)… (CRC32 $00000000: (Apple_Free : 3)) Adding resources… Elapsed Time: 1.864s File size: 11023 bytes, Checksum: CRC32 $A711D232 Sectors processed: 500469760, 11 copied Speed: 3.0Kbytes/sec Savings: 100.0% Operation successful.
The problem, however, is that I am trying to do this on a 256 GB Bootcamp partition but the dmg created is only 11kb. It only takes a second to generate it as well.
Why is Disk Utility not copying the drive? Can I use dd directly on the bootcamp partition instead?
Thanks in advance!
I noticed that although my dmg is only 11kb when I continue on and use hdiutil:
hdiutil convert -format UDTO -o BOOTCAMP.img BOOTCAMP.dmg
hdiutil convert -format UDTO -o BOOTCAMP.img BOOTCAMP.dmg Reading Master Boot Record (MBR : 0)… Reading (Apple_Free : 1)… Reading (Type 72 : 2)… Elapsed Time: 36.230s Speed: 6.6Gbytes/sec Savings: 0.0% created: /my path to my folder/BOOTCAMP.img.cdr
The output file is 115GB. Perhaps someone with more knowledge about Disk Utility could explain how the dmg works? Is it just referencing the Bootcamp partition in some way? Or is this 115GB file just garbage?