Can I run El Capitan on an external drive to test legacy apps on Mac internal drive?

[Inuevo]

Before upgrading from Lion 10.7.5 on my late 2011 17" MacBook Pro, I want to check which of my old apps will work with which newer OSs. From reading roaringapps.com (thanks to advice from a previous post) it seems that nothing between Yosemite and High Sierra suits all the apps I've got so I need to experiment to find the optimum version. If I install, say, El Capitan on an external drive and boot into that, can I try out my old apps that are only on my Mac internal drive, or do they have to be on the external drive too?

Thanks.

 

[Slydude]

You should be able to have the OS on an external drive and the apps on the internal drive. I've done it before and I don't remember having any issues.

It would also be possible to have everything on the external drives (apps included) but that means taking time to clone the drive including all apps. I have one external drive with the last 3 or 4 OS versions for all kinds of situations like this.

 

[Inuevo]

You should be able to have the OS on an external drive and the apps on the internal drive. I've done it before and I don't remember having any issues.

It would also be possible to have everything on the external drives (apps included) but that means taking time to clone the drive including all apps. I have one external drive with the last 3 or 4 OS versions for all kinds of situations like this.

Thanks, that's encouraging and sounds like the easiest option to start with. I have considered cloning but I'm wondering if the method I've read about is considered the best:

1 – clone the Mac drive to an external drive,

2 – then update the Mac's OS to, say, El Capitan.

3 – test legacy apps and if they don't work wipe the Mac drive and restore the cloned backup to it.

Have I understood that correctly? It seems to me that a less risky approach which not would involve wiping the Mac drive would be to:

1 – clone the Mac drive to an external drive,

2 – then update the clone to El Capitan.

3 – Boot into that, and if the apps don't work abandon it and go back to the untouched Mac drive.

Is that not a better way of doing it, or am I missing something?

 

[ferrarr]

If I install, say, El Capitan on an external drive and boot into that, can I try out my old apps that are only on my Mac internal drive, or do they have to be on the external drive too?

No, you would need to install the apps (you want to test), to each version of OS X/macOS you want to test.

Also, do you have the installers, for all the versions of macOS, already associated with your Apple ID? Are they already downloaded to your Mac, or are they listed in your Mac OS X App Store Purchased page?

Edit: Just as an FYI, Macs have the ability to boot into any suitable OS X/macOS version, provided your Mac meets system requirements.

 

[gsahli]

No, you would need to install the apps (you want to test), to each version of OS X/macOS you want to test.

I don't think that's correct Bob. I think you can just double-click to run any application, and see if it works in the OS version you're booted in. Hope someone else chimes in.

 

[pm-r]

I don't think that's correct Bob. I think you can just double-click to run any application, and see if it works in the OS version you're booted in. Hope someone else chimes in.

I agree and with what Slydude says.

But be aware that some applications will only run when installed on the boot volume, assuming they are compatible.

And if they aren't, just keep and run such apps buy booting the appropriate volume and then running the app.

In my case, I keep several bootable volumes/partitions: 10.6.8 Snow Leopard, 10.9.5 Mavericks, 10.12 Sierra.

In some cases I have aliases to the application I may need or want, other times I have to boot into the particular volume where the application will run. It actually sounds more involved than it actually is, and things usually just work.

It's just that sometimes there is the odd application that is not normal, or it may need something that a later OS X version removed.



- Patrick
======

 

[pm-r]

If I install, say, El Capitan on an external drive and boot into that, can I try out my old apps that are only on my Mac internal drive, or do they have to be on the external drive too?

BTW: Were you planning on using Migration Assistant to migrate your data and settings and applications from your old volume to the new El Capitan installation???

Why not do so and then you can save yourself a lot of work, and you will already have a backup of your old volume and then just use the applications to test how they all work work.


- Patrick
======

 

[Inuevo]

I take your point about Migration Assistant. Thanks. Do you have a view on the cloning option which I added to my reply to Slydude?

 

[pm-r]

I take your point about Migration Assistant. Thanks. Do you have a view on the cloning option which I added to my reply to Slydude?

Either would probably work but your second suggested method would probably be earier and is a method I have used several times.

BTW: I normally just use CCC (Carbon Copy Cloner) for cloning and wiping any data (default) from the Target volume/drive/partition. One operation.


- Patrick
======

 

[ferrarr]

Just as an FYI, if you upgrade MacOS X/OS X/macOS, some apps may work with the upgrade, it's when someone does a clean install of Mac OS X/OS X/macOS, where apps stop functioning properly.

Which versions of Mac OS X/OS X/macOS do you downloaded or in your Mac App Store Purchases?

 

[Inuevo]

Just as an FYI, if you upgrade MacOS X/OS X/macOS, some apps may work with the upgrade, it's when someone does a clean install of Mac OS X/OS X/macOS, where apps stop functioning properly.

Which versions of Mac OS X/OS X/macOS do you downloaded or in your Mac App Store Purchases?

I haven't downloaded any upgrades yet as I'm still at the planning stage. My current set-up has served me well for 7 years with no updating, so you can tell I'm not the sort of user who feels the need to rush these things! But the time has come, I think, to bring it all a little more up to date. I will report back on how I get on when I've decided which of the helpful suggestions to follow.

Thanks all.

 

[Rod]

Ineuvo hi, do you have a lot of legacy apps or just a few you really want?

If there are only a few you could check with the developers (if they are still around) if their apps are compatible with later versions of macOS.

If you have a lot or the developers are unavailable I would suggest the clone method you suggested first in #3.
I would consider just keeping the clone to run your legacy apps from unless you do that a lot while updating your computer to a current OS.

You can copy apps from the external clone to your computer at any time you come across a compatible update.

Speed is another issue you may need to consider. A USB External drive will be slow if you need to boot from it. Ideally an external SSD with a USB-C or Thunderbolt connection would be good but any external SSD will speed things up a bit.


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