#Airport disk archive full#

When the drive is full the Time Machine deletes old backups to free space for new data. The Time Machine keeps adding backup files as long as there is enough space on the backup disk. The Time Machine does not create monthly backups. After 24 hours it creates a daily backup for one month and weekly backups for multiple months. The Time Machine keeps up to 24 hourly backups. If the Time Machine is set to back up automatically it will run once every hour. After that, the Time Machine only saves contents of files that have changed since the last run and uses hard links to the previously backed files and folders to optimize the storage and speed up the backup process How often does Time Machine backup 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.

#Airport disk archive software#

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. If you buy through affiliate links, we may earn a commission at no extra cost to you.