How to disable Time Machine

[Demovx]

Hi!

I have problem with boot external disk.
My disk in my imac ( internal) is clean.
I use external ssd disk usb.
When i power up my Mac, first boot the internal ( clean) but "time machine" disk.
I disable in settings time machine but still auto boot first with the clean ( no TM) internal.

How can i disable all time TM on high Sierra?

 

[simonsi]

Have you correctly set the startup disk in Preferences?

 

[sylvie.petit]

· Uncheck “Back Up Automatically”

· Remove the current backup disk.

· Select “stop” option to disable using the disk

 

[wesley96]

This issue isn't about disabling Time Machine, as far as I can tell.

As I understand it, you want your Mac to boot off an external disk (USB SSD).
But it it keeps trying to boot off the internal disk, which you're using as a Time Machine disk.
You want to stop the system from booting off the internal disk.

Disabling Time Machine function will NOT solve the problem because this is about Startup Disk priority. Whether the disk is used for Time Machine or not is irrelevant. As simonsi noted, you need to check the Startup Disk setting in the System Preferences. Try assigning the external disk as the startup disk there.

Now, if this does not work, then it may be that the USB disk is becoming active too slow for the system to recognize and use as a startup disk.