I was told than having more than one OC enabled HDD installed at the same time can cause problems.....
What you were actually told:
The issue is not about having one than one OCLP instance per se, but in having more than one OpenCore ESP regardless of whether created via the OCLP or not. So, you can have 100 Mac OS instances set up to run via OpenCore without issue as long as they are run from one ESP.
You seem to have assumed, at some stage previously at least, that there is something called an "
OC Enabled Disk" required to use OpenCore whereby every disk with an unsupported Mac OS instance should have an associated OpenCore instance installed in the ESP of that disk
However, while disks formatted as APFS or HFS+ have ESPs and OpenCore is installed to such, you are not meant to put OpenCore into the ESP of every disk you want to run unsupported Mac OS instances from
What is needed is to have OpenCore on the ESP of
one and only one of the disks in your system. It doesn't matter which one of the disks it is as such, or which tool you use to implement OpenCore, as long as there is only one ESP with OpenCore (properly configured to run the unsupported Mac OS instances) present
As an aside on this...
MyBootMgr/RefindPlus overcomes this problem?
Note that there is nothing called "MyBootMgr/RefindPlus". There is MyBootMgr, there is RefindPlus and there is OpenCore; all of which are totally different and separate things. If you had read
POST 1
, you would have found this:
The tool/process used to implement OpenCore is a secondary matter but I can give you the steps to take with MyBootMgr based on my understanding of your setup:
- You are running a MacPro3,1 (MP31)
- You have a disk with El Capitan installed
- You have a disk with Monterey installed (May have had patches applied by the OCLP)
- You have OCLP configured OpenCore on the ESP of the disk with Monterey
- You have at least one GPU natively supported on El Capitan
- You have a Sapphire Pulse RX580 available
Based on these, given your past issues, you need to do the following:
- From El Capitan, with the natively supported GPU in, revert any OCLP patches applied to Monterey
- Rigid patches as applied by the OCLP are not needed/desirable for Monterey on MP31 with RX580
- Patches may have been applied to Monterey by the OCLP when run from El Capitan with the old GPU
- From El Capitan, mount the ESP on the Monterey disk and delete everything under the EFI folder
- That is, all sub-folders and contents ("BOOT", "OC", "System" ... whatever)
- If you have also put OpenCore on the ESP of the El Capitan disk, similarly mount and clear
- Shut down, disconnect the Monterey disk, and execute a "Deep NVram Reset"
- You should be automatically booted into El Capitan
- Stop here and get back if not so
- From El Capitan, set El Capitan as the start up disk in System Preferences and shut down
- Reconnect the Monterey disk and boot into El Capitan
- Download and run the MyBootMgr dmg to install MyBootMgr's "Helper Apps"
- Afterwards, execute Step 3 of "IMPLEMENTATION >> STAGE 1 - PREPARATION" of
POST 1
- Shut down when done with Item 4 above, swap your RX580 in, then restart
- Execute "IMPLEMENTATION >> STAGE 2 - INSTALLATION" of
POST 1
- RX580 is painfully slow and glitches like mad on El Capitan but you'll live
- Run the ConfigFactory app in "DUAL" mode to install RefindPlus and OpenCore
- Select a volume that is definitely *NOT* on the El Capitan disk and preferably *NOT* on the Monterey disk as target volume when the question comes up in ConfigFactory
After completiing the steps above...
- You will be able to boot as follows:
- Monterey via OpenCore
- El Capitan via OpenCore and/or RefindPlus
- Refer to "IMPLEMENTATION >> STAGE 3 - CUSTOMISATION" of
POST 1
to incorporate Sonoma
- Do not add another ESP with any OpenCore, including by the OCLP, or worse still, overwrite the MyBootMgr created ESP, but incoporate Sonoma into the MyBootMgr created setup as instructed in that section
- Consider installing DosDude Mojave/Catalina to run RX580 without slowness/glitches for future MyBootMgr updates etc
- Should you, do not indicate that you intend to boot your DosDude instance via OpenCore when the question about patched instances comes up while running ConfigFactory. DosDude instances should always be run via RefindPlus and you will essentially not have a DosDude instance for consideration with OpenCore
Using MyBootMgr to set things up requires that you do not read "
Do Action C" in
POST 1
and decide on "
Action K" instead:
Forget about whatever you might have read elsewhere and follow the instructions verbatim.
Please look for answers in
POST 1
first and only post back if something is not covered there.
Good luck!
Edit: Removed DosDude Mojave aspect from the outlined steps as likely not doable at this point ... must suffer RX580 on El Capitan initially