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I installed a 500gb SSD in my Macbook and created an extra partition there with 100gb. Now I want to merge the partition back into the SSD but unfortunately I always get an error when I press restore. What did i wrong?
Not understanding why you are restoring. First you do want to make a good backup of both partitions independent of each other TimeMachine will only do the primary (boot volume) so your second volume won’t be backed-up. As you have a small volume just copy the data off to an external drive. Now what is important here is the partitions type may not be compatible with each other and the data held might not be accessible within the Mac apps (I.E. Ms Windows or Linux) You also need to use disk utility to delete the second partition then you can extend the primary, and lastly copy back your stuff.