Modifying this control will update this page automatically
Mac User Guide
- Welcome
- What’s new in macOS Sequoia
-
- Get started with Apple Intelligence
- Use Writing Tools
- Use Apple Intelligence in Mail
- Use Apple Intelligence in Messages
- Use Apple Intelligence with Siri
- Get webpage summaries
- Summarize an audio recording
- Use Apple Intelligence in Photos
- Summarize notifications and reduce interruptions
- Apple Intelligence and privacy
-
- Intro to Continuity
- Use AirDrop to send items to nearby devices
- Hand off tasks between devices
- Control your iPhone from your Mac
- Copy and paste between devices
- Stream video and audio with AirPlay
- Make and receive calls and text messages on your Mac
- Use your iPhone internet connection with your Mac
- Share your Wi-Fi password with another device
- Use iPhone as a webcam
- Insert sketches, photos, and scans from iPhone or iPad
- Unlock your Mac with Apple Watch
- Use your iPad as a second display
- Use one keyboard and mouse to control Mac and iPad
- Sync music, books, and more between devices
-
- Control what you share
- Set up your Mac to be secure
- Allow apps to see the location of your Mac
- Use Private Browsing
- Keep your data safe
- Understand passwords
- Change weak or compromised passwords
- Keep your Apple Account secure
- Use Mail Privacy Protection
- Use Sign in with Apple for apps and websites
- Find a missing device
- Resources for your Mac
- Resources for your Apple devices
- Copyright
If the identity of a backup disk has changed on Mac
For security, Time Machine won’t do a backup if it detects that the identity of your backup disk has changed. This can happen for several reasons:
You erased or reformatted your backup disk or partition.
You deleted the disk image for your backup disk.
Someone is trying to steal your information by tricking your Mac into backing up to an unauthorized disk.
If you connect another disk to your Mac, give it a different name from your backup disk. Then make sure your backup disk is correctly identified. On your Mac, choose Apple menu
in the sidebar, click Time Machine , then reselect your backup disk.
Thanks for your feedback.