Q: format backup?

    When trying to use Time Machine I get this message message "The backup disk is not in Mac OS Extended (Journaled) format, which is required" The disk is ntfs and copies files from the directories, but won't allow use of Time Machine.

Model Name: MacBook Air

  Model Identifier: MacBookAir5,1

  Processor Name: Intel Core i5

  Processor Speed: 1.7 GHz

  Number of Processors: 1

  Total Number of Cores: 2

  L2 Cache (per Core): 256 KB

  L3 Cache: 3 MB

  Memory: 4 GB

  Boot ROM Version: MBA51.00EF.B03

  SMC Version (system): 2.4f19

  Serial Number (system): C02K54JQDRV6

  Hardware UUID: 59362C32-A179-563F-BBDF-BE34786243A6