I want backup my MacBook on my external Hard Drive, but when I trying to use time machine, it shows I should format my hard drive.

Is there any way to give backup without formatting hard drive ?

  • More information is needed here. Do you want to connect your external he'd via usb or via the network? How much space is on your hdd? You could possibly shrink the partition to make space for a second partition to be us d for the time machine?
    – Rainer
    Sep 18, 2014 at 19:43
  • Time Machine doesn't want to 'share' with any existing file structure, it wants a partition to itself.
    – Tetsujin
    Sep 18, 2014 at 19:54
  • 1
    But repartitioning could solve the problem. One partition with the existing data and the second one for time machine.
    – Rainer
    Sep 18, 2014 at 19:58
  • @Rainer I connected my 500GB external HDD via USB to my MacBook, and have just one NTFS partition
    – MajAfy
    Sep 19, 2014 at 5:46
  • @Rainer so I will shrink my HDD to use for time machine, thanks for your guide
    – MajAfy
    Sep 19, 2014 at 5:49

2 Answers 2


According to the Time Machine documentation it requires a HFS formatted drive to work.

To get around this problem, on my external FAT32 USB drive, I split it into two partitions. One for Time Machine, in HFS, and the rest for FAT32 to share files.

In you case, since it already has files, I would find a tool to shrink the existing partition, then create a new HFS one in the now free space and voila! Your problem is solved. If the existing filesystem is NTFS then Windows Vista and above I think will happily shrink it. If FAT32 then have a look here.


Absolutely. You could boot to recover HD and use Disk Utility to make a compressed image of the drive. It's not as handy as Time Machine but would allow you to not erase the drive that will contain a backup of things as they are.

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