The Time Machine does a full backup only for the first time. So, with this knowledge we can answer the following question: Does Time Machine do a full backup every time To optimize further, in case if the folder did not change since last backup TM creates a hard link on a folder instead of thousands of hard links on each file inside the folder so the incremental backup runs very fast. So, if initial backup copied 100,000 files and only one file has changed since then only one file will be copied during the second backup.

Now if we make a change to fil1.txt then when next backup runs TM will copy file1.txt to a new folder and create a hard link to file2.txt from a previous backup without copying its contents. For the files that have not changed, it creates hard links that point to the actual files in a previous backup.įor instance, if initially, we had two files: file1.txt and file2.txt, they both will be copied on the first backup. When TM runs next time it only copies files that have changed to a new folder. When the first backup runs Time Machine copies all files from a startup disk to a new folder on the backup disk. Time Machine (TM) on Mac uses hard links (wiki) concept to create backup folders. After the backup was done it is possible to restore individual files, applications or entire storage to a previous version. When it runs first, the Time Machine makes a full backup and performs incremental backups after that. Time Machine is a free built-in backup software which copies Mac disk contents to external storage. While I was doing different experiments on my MacBook, I always knew that I can restore the contents of my MacBook to the working state because I have made backups with the Time Machine.

Mac network drive does not disconnect