Working with Bootcamp Partition (backup, restore, resize)

Thrilla-C wrote:

I recently installed Windows 10 (using Bootcamp) on my Late-2009 iMac (21.5") (macOS 10.13.6 High Sierra). I know this is an unsupported configuration. I am planning to use the Windows environment almost exclusively from this point forward (more friendly for my current "work from home" situation). Now that my bootcamp data is more important, I have a couple of questions.

1) I created an image (.dmg) of my bootcamp installation right after it was installed. I booted into macOS and used the Disk Utility (File -> New Image -> Image from "BOOTCAMP"). If I ever need to restore my windows environment, can I simply use the Disk Utility to "Restore from Image?" or will there be problems? I've heard disk utility doesn't always play nice when working with NTFS volumes (not sure if it matters whether the source, destination, or both are NTFS).

There will be problems. My recommendation is to buy an external disk, format it as NTFS when booted in Windows, and use it to backup Windows. If you need to restore, wipe the Windows installation, re-install Windows and restore your external disk backup. You can also look at Winclone as an option.

2) What if I want to resize my bootcamp partition? Assuming my .dmg images can be restored, my current plan would be to create a new image of my bootcamp partition. Use Bootcamp Assistant to delete existing windows partition, then recreate a new partitions of the desired size. Finally use Disk Utility to restore my previous environment into its new, bigger, partition. Will this work?

Do not resize Windows and do not use Disk Utility. Choose the size properly. If you are using Windows exclusively, use the entire internal disk for Windows. Install macOS on an external disk, for emergencies.

I have bootable USB drives with both macOS 10.13 and Windows 10. I a little experience with command line tools and 3rd party partitioning utilities, although I rarely use any of those in the Mac world (usually only with windows/linux).

The external macOS boot is much cleaner.

1. Use a Windows backup program to back up Windows and data from the Windows partition.
2. Use Disk Utility to remove and recreate a Boot Camp partition of the correct size. Reinstall Windows using Boot Camp Assistant. Then restore your data from your Windows backup.

But if this is an unsupported configuration then there are no guarantees that anything will work.