Running both Mojave & Catalina OS Systems

Currently my Mac is running Mojave and I have a Windows 8 Guest OS. I have a Windows app that is a 32-bit one and I've confirmed that the Windows Guest OS will still be able to run that app if I upgrade to Catalina. However I have a Mac app that is a 32-bit one so it won't run if I upgrade my Mac to Catalina. I've checked and this app is not going to be upgraded to 64-bit. I've not found a comparable 64-bit app so I'd like to be able to run this app after I upgrade.

I was thinking that the solution might be to have a Guest OS running Mojave after I upgrade to Catalina and just have this Mojave OS running the 32-bit app. Would this be feasible and how would I go about making this change?

 

Hello @RobbieSnr Yes, you may have a Mojave version of macOS installed via Parallels to run your 32bit Applications. However, we would like you to inform that macOS Catalina is not currently supported with Parallels Desktop. You can install macOS Mojave as VM and continue using it and upgrade your host macOS to Catalina once it is officially released.

 

Many thanks for your reply. To install the guest Mojave OS do I just go for the option in the Control Center to install Mac OS 10.14.6 from the recovery partition? Presumably this would install all my existing apps into this guest OS and I could then delete the ones I don't want, continuing to run my host Mojave OS as my main Mac OS.

 

Hello, @RobbieSnr Please be informed that installing macOS using Parallels Installation assistant from Recovery Partition will only install as a new Virtual Machine and will not have your applications from Host OS, you need to reinstall them manually.

 

Noted, thanks Abishek. This is fine for what I want.

 

I was thinking that the solution might be to have a Guest OS running Mojave after I upgrade to Catalina and just have this Mojave OS running the 32-bit app. Would this be feasible and how would I go about making this change?

 

I was thinking that the solution might be to have a Guest OS running Mojave after I upgrade to Catalina and just have this Mojave OS running the 32-bit app. Would this be feasible and how would I go about making this change?

 

Zimz, what are you actually suggesting - you just seem to be quoting what I've just said?

 

Once, we have Mojave running as a Guest OS on Catalina, could we then run Mac migration assistant to recover the apps from a recent backup of Mojave?

 

Yes, I have just done this.
Dis a fresh time machine backup before starting the upgrade to Catalina. Made sure I had a downloaded Mojave install available.
Then created a new VM, using this installer.
Gave quite a few issues. Parallels seems to have a bug when you do the Mojave install. Hangs forever (over 13 hours, till I gave up), when it starts the install. The fix was before actually beginning the install, to go into disk manager and convert the virtual drive to APFS. The install tries to do this conversion, but it's version hangs. the Disk Manager version did it fine. Have reported it to Parallels, but since I have found a way round it, they didn't seem terribly interested.
Then once running, installed Parallels tools, and used the migration assistant to copy back the programs I wanted.
So I now have Catalina running, with a Mojave VM available, and the 32bit stuff on this.

 

Is there a way to open app from the host OS (like Windows as the host, MacOS as the guest or vice versa?) I don't want to install a lot of apps I have installed in the Host MacOS in the guest MacOS, but there seems to be no option to open the file with the guestOS from the host.

 

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I'd like to know the answer to this too....

 

Hey, all it was really confusing but now all is ok. thanks, ZIMZ for your reference. EMI Calculator Calculate the EMI

 

Hum... I tried it this way, but the Mojave guest's Migration Assistant didn't find or accept the external hd drive, even though it's been mounted in this guest.
The only difference to your configuration is that I have a simple mirror backup (instead of a Time Machine backup), that is: an external bootable mirror of my Mojave installation.
When I start the migration assistant from within the Mojave guest, this app looks for a source to migrate. In my opinion, this should be present in the external drive. But the MA refuses to use it.

Someone there with a hint?

Thanks in advance!

 

How did you mount the backup volume?
With my mirror backup (not Time Machine) it didn't work. See my former post.