I have an 2 TB external hard drive. It is formatted as NTFS format, supported by ntfs-3g which is installed using Homebrew. There is already about 500 GB data existing on it that I need to keep. I now want to use the rest of the space on it to store my TimeMachine backups. There is only one partition on the hard drive. I do not have other hard drives to shuffle the data. How can I start to use this hard drive to store my Time Machine backups?

  • Would you not just use some third party application such a GParted to shrink the NTFS partition and add a new JHFS+ partition? To make a bootable GParted see "How to make and use an USB stick with GParted that will boot on a Mac?". Dec 8, 2019 at 11:45
  • Do you have access to another machine that is running Windows? Dec 8, 2019 at 11:55
  • I got impatient and burned the data I really need to keep into a DVD. Now I'm ready to just erase everything on the hard drive create two partitions, one NTFS, the other APFS. How to do that?
    – qazwsx
    Dec 8, 2019 at 13:07
  • @qazwsx Not APFS. Time Machine can only use HFS+.
    – benwiggy
    Dec 8, 2019 at 16:47
  • I think you are wrong. I just finished saving TimeMachine backup on one of the two new APFS partitions. Now I just need to figure out how to change the other APFS partition to NTFS for storing and sharing other data on macOS and Windows machine. Any tip?
    – qazwsx
    Dec 9, 2019 at 2:51

1 Answer 1


Time Machine can only work on a volume formatted as HFS+. So you will need to repartition this drive. A quick Google shows that it is possible to resize an NTFS partition, but this can't be done with Disk Utility on MacOS.

I wouldn't recommend playing with the partitioning on the volume if the 500Gb of stuff isn't also backed up somewhere else.

  • It is NTFS. I added the info in the post.
    – qazwsx
    Dec 8, 2019 at 10:46
  • 1
    I wonder if you can create a sparse disk image on the drive and backup to that? I have done similar things over a network onto a Windows PC but not sure if it will work with a local NTFS drive that has a mounter sparseimage on it... Dec 8, 2019 at 16:44

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