using an external hard drive on two different macs

I currently have an iMac with an external drive. I am planning to sell my iMac and purchase a MacBook. Will it be a simple thing to just plug in my current external hard drive and carry on with my new MacBook?

iMac 27″ 5K, macOS 13.6

Posted on Mar 12, 2024 11:10 PM

Reply
Question marked as Top-ranking reply

Posted on Mar 13, 2024 9:04 AM

I answered in my first post when I said, "If it is just general external storage no problem...." and because it is less than 5 years old it should be fine.


By the way, do you have a Time Machine External Hard Disk that you use to backup to? If you do not this is ABSOLUTELY critical that you fix this problem before going to your new machine. Operating any computer without a backup is a 100% guarantee that you will lose valuable data such as your photos, music, important documents, etc.. If you are not aware of Time Machine please refer to Back up your Mac with Time Machine. Time Machine requires an external HD. not the same one you use for data it must be dedicated to Time Machine only!!!! The External Hard Disk many experienced users on these forums use is the OWC Mercury Elite Pro.


Finally, when you get your new MBP, please follow the instructions below for migrating to the new computer!!


When you buy a new Mac the easiest, quickest and most reliable method to migrate from the old Mac to the new Mac is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. You will likely need a USB A to USB C adapter, you can find them on Amazon for $10 or less. When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes  and follow the on-screen prompts and it's done! It is THAT simple.

 

If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts. 

 

The ONLY difference between MA and SA is MA will create a new user account that you need to log into.

 

Both SA and MA migrate applications (not 32 bit apps), data files & settings. They do not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not an issue. 

 

Finally, never EVER use Wi-Fi when doing Setup Assistant or Migration Assistant. Why, it simply fails in most cases. Please read and follow the directions in Setup Assistant and Migration Assistant. If you do not have a Time Machine backup of the older Mac then create one! If you are not aware of Time Machine, please read Back up your Mac with Time Machine and finally if you need an External Hard Disk to use as a Time Machine External Hard Disk then many experience users on these forums prefer the OWC Mercury Elite Pro due to it's reasonable price, high level of quality and ease of use. 


Similar questions

3 replies
Question marked as Top-ranking reply

Mar 13, 2024 9:04 AM in response to Daizy-jar

I answered in my first post when I said, "If it is just general external storage no problem...." and because it is less than 5 years old it should be fine.


By the way, do you have a Time Machine External Hard Disk that you use to backup to? If you do not this is ABSOLUTELY critical that you fix this problem before going to your new machine. Operating any computer without a backup is a 100% guarantee that you will lose valuable data such as your photos, music, important documents, etc.. If you are not aware of Time Machine please refer to Back up your Mac with Time Machine. Time Machine requires an external HD. not the same one you use for data it must be dedicated to Time Machine only!!!! The External Hard Disk many experienced users on these forums use is the OWC Mercury Elite Pro.


Finally, when you get your new MBP, please follow the instructions below for migrating to the new computer!!


When you buy a new Mac the easiest, quickest and most reliable method to migrate from the old Mac to the new Mac is to simply connect the old Mac's Time Machine External Hard Disk to the new Mac using a USB cable before you turn on the new Mac. You will likely need a USB A to USB C adapter, you can find them on Amazon for $10 or less. When you start the new Mac for the first time it will startup Setup Assistant (SA), SA will get to a point where it asks if you are migrating from another computer, select Yes  and follow the on-screen prompts and it's done! It is THAT simple.

 

If you have already done SA on the new computer then simply connect the Time Machine External Hard Disk using a USB cable and launch Migration Assistant (MA) which is located in Applications - Utilities - MA. Then follow the on-screen prompts. 

 

The ONLY difference between MA and SA is MA will create a new user account that you need to log into.

 

Both SA and MA migrate applications (not 32 bit apps), data files & settings. They do not migrate Mac OS itself. Some professional apps such as Adobe and Microsoft apps may require re-installing their apps as they will not allow them to be migrated. As long as you kept the security keys for installing their apps, it is not an issue. 

 

Finally, never EVER use Wi-Fi when doing Setup Assistant or Migration Assistant. Why, it simply fails in most cases. Please read and follow the directions in Setup Assistant and Migration Assistant. If you do not have a Time Machine backup of the older Mac then create one! If you are not aware of Time Machine, please read Back up your Mac with Time Machine and finally if you need an External Hard Disk to use as a Time Machine External Hard Disk then many experience users on these forums prefer the OWC Mercury Elite Pro due to it's reasonable price, high level of quality and ease of use. 


Mar 12, 2024 11:32 PM in response to Daizy-jar

What do you use the External Hard Disk for? If it is just general external storage no problem, however if you use the External Hard Disk as a startup drive then no it will not work until it's setup correctly.


Finally, if the External Hard Disk is 5 years old or older, just replace the thing. All HD's wear out and 5 years has been a good life, over that then it could fail at any time.


One other thing I forgot, if the drive is a USB A-B connection you will need an adapter as all new Macs have USB C ports. You can buy the adaptors from Amazon for less than $10.

Mar 13, 2024 1:02 AM in response to rkaufmann87

I use it for Microsoft Office mainly but also have photo's stored on there and a few other documents etc, but no I don't use it as a start up disk as I only plug it in when I want to find photo's or use Office.

So will this be ok to just plug in a new MacBook and carry on using?


It is a Seagate 3TB model: SRD0NF2

Not sure if this can shed any further light on it?


I definitely bought it less than 5 years ago.


My iMac is a 2017 model so I'm assuming I would need the adapter you have mentioned but this isn't a problem.

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

using an external hard drive on two different macs

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.