How to shrink an existing bootcamp under High Sierra

Hello. Does anyone know how to shrink an existing Bootcamp partition via WinClone 6.1.8 running in High Sierra?

I have tried this but it just gets hung up.

It gets stuck at Validating volume size: Pass 2 . The progress bar is right under the “V” of “Validating volume size: Pass 2” onscreen message. And then hangs there while my iMac fan gets louder for several minutes. And then it just hangs. Is it even possible to shrink existing Bootcamp partition filesystems from Winclone in High Sierra now?

One more question: when I originally created this Bootcamp partition it was in MS-DOS format. As I was restoring the Winclone image for it via Winclone, it stayed it MS-DOS format as I was checking it via diskutil info via the terminal. Then sometime right around the point where Winclone stated “Expanding filesystem” in the restore process, the filesystem for the Bootcamp partition turned into Windows NT. Is that normal for a Windows 10 Bootcamp partition? Under High Sierra ??

Are you shrinking the filesystem or are you saving a disk image? In order to shrink the space used by Windows, you need to make a Winclone image, remove the partition, create a new, smaller partition, then restore. If Winclone is set to use WIM (file-based) imaging, you don’t have to do anything prior to making the clone. If you are using blockbased imaging, you need to shrink the filesystem first so that it restores to a smaller partition.

Either way, make sure you have good backups of all files on any partitions on the drive, since repartitioning can expose any flaws (fatal or otherwise) on the drive. If you want to do this dynamically, check out iPartition. It can resize a Windows NTFS partition without removing the partition.

When you restore a block-based image, the NTFS filesystem is restored when the blocks are restored. Winclone requires MS-DOS format just to indicate that it is a valid partition to restore to. I didn’t want to give the option of restoring to HFS+ / Mac formatted drives since it would increase the chance of data loss if someone restores to an incorrect partition. It also sets the partition ID in the MBR, but that isn’t really needed any more.


Thanks Tim.

Does this mean that if I use WIM imaging to make the clone of the Bootcamp partition, AND I want to reduce the size of the Bootcamp partition to slightly larger than the size of the WIM version of the clone…then do I need to need to remove the Bootcamp partition and create a new one after making the WIM version of the clone? And then resize it to what I want? And then restore the new WIM clone?

I looked all through the online manual and couldn’t find it. Maybe I was just missing it!

Appreciate your help and thanks.

If you use WIM based imaging, you don’t need to do any shrinking. It restores just the files and permissions.