With the problems presented by recent releases of OSX this could be a safe way of testing compatibility issues
With High Sierra, Mojave & Catalina.

https://www.macworld.co.uk/how-to/mac-software/macos-external-drive-3659666/

also

https://www.makeuseof.com/tag/mac-boot-from-usb-drive/

 

I wanted to go from my current Sierra system to High Sierra. I cloned my system on an external and installed High Sierra onto it. Even though Superduper says it creates a bootable clone, fukk me if I can ever get one to work. I looked around and Apple seems to have really made it difficult, if not impossible, for booting off an external to work anymore for the past few OS iterations that I know of.
I recall I had gotten it to work by using a USB 2.0 drive when I was messing around testing something a while back. But I mean really... a mac with usb 3 ports, but it'd only boot from a usb 2??? wtf apple.

Sure I have an app that'll create a bootable system from a usb stick or hdd, but that's just from installing the OS alone onto it. All the software I use is of course not installed.

I said fukk it and made another partition on my mac hd, cloned my system onto it and installed HS. So therefore all my apps and plugins can be tested.
However, I am now wondering if it was possible to boot just the newer OS from an external, which as I say I can make that, and would I then be able to run my DAW and plugs that reside on the internal system hd? Off the top of my head I'm thinking no because the DAW and plugs have components that sit inside specific system library folders. And those are obviously on the internal mac hd and not in the library of the system booted from the external.

 

Last edited: Oct 17, 2019

Upgraded my son's Macbook Air to High Sierra from Yosemite with no issues other than it took a few restarts to complete & stick. Was thinking about upgrading to Mojave but, saw the same cautions for Catalina. That's when I found the two articles mentioned.

Like everything else. One persons solution is another persons headache.

 

Last edited: Oct 17, 2019

No that won't work. With some plug ins with larger libraries (say Superior Drummer, Omnisphere, Kontakt, what have you), you can make an alias or symlink to another drive, but you can't have a barebones system drive address plugins etc from another drive, as there are so many different files installed that they look for from application support, to licenses , and whatnot.

 

another option is, make a full bootable backup (on external drive) of current OS with use of Carbon Copy Cloner (<- THIS is the reliable backup/clone solution for MacOS! - for hackintosh, EFI partition with Clover is cloned empty, so all contents need to be copied manually, just sayin' ;), and just upgrade your main OS system directly - that way testing reperesents real scenario better, because it includes original internal drive and its read/write/seek speeds

 

Yeah, since I don't have the time I need to properly clean install as often I should, I always Carbon Copy clone to another drive before updating something major like an OS for sure. And always have a backup of my current system carbon copy cloned on a 1TB spinner (matching size of my SSD boot drives), so worst comes to worst, I can finish something on a deadline with a bootable system rather then mucking around or waiting for Time Machine etc. AND Carbon Copy Cloner (the reason I switched from Super Duper a few years ago) copies the recovery partition as well, which in this day and age is important. Super Duper says they do now, but for awhile they did not, and CCC works just fine for me.

 

Ah, ok, thought as much. confirmed then, thanks.

So you guys are saying you have no problems booting from an external hdd using CCC? And SD doesn't even though the damn thing says it makes the clone bootable? I've got to get a hold of their tech support regardless on this.

At the time, I basically had a 50-50 decision in choosing either CCC or Superduper. SD seemed to have the better reviews iirc, so I picked that one, lol.
I'm perplexed as to why I can't boot a clone of my mac hd using SD as opposed to CCC if true. That would be a major failing on SD's developers part. I'll switch if need be.

 

You should have no problem booting from an external HDD using Superduper, as I did it for years, and even recently I booted from an old 10.6.8 drive cloned with SD and was all good.... I remember something about seeing or ticking an option for making the clone "bootable", but tbh, I can't remember if it was in SD, CCC or something else entirely....

but yeah, I would contact their support, as there is no reason it shouldn't boot from an external drive... unless something in your mac or whatnot is prohibiting it... (like say, you can't boot off a drive connected to a usb 3 card in a cheese grater or something along those lines...)...

but I routinely boot from my current clones, a. to make sure they 'work', and b., to do say disk warrior or drive genius tasks from another drive that you can't do from the drive you are booted from...

 

Thanks. Hmmmm definitely got to get tech support. At the end of Superduper process it checks off 'make drive bootable' . So I don't know what the heck is wrong.

When I went from Mavericks to Sierra a couple years ago I had also bought some new external (seagate) drives. I was getting errors formatting some to mac. I tried on my snow leopard macbook and no problem. Never had this problem before Sierra.

I looked around and found something about this (disk1??) hidden EFI thing that may be the culprit and actually found a solution to delete it. I had to use my pc laptop to get rid of it and I was able to format with Sierra with no issue.

Never had any problems using any of my many externals that I have formatted under various OSX incarnations. But is it possible that I'm using an external that was formatted when I was using an older OSX version that that could be the problem?

 

Last edited: Oct 17, 2019

What kind of drive are you cloning to? A usb external or whatnot?

 

How did you format the drive? As in what filesystem?

 

In this particular case of making a High Sierra test system, what external hdd space I had available at the moment was to make a partition on a seagate 6tb usb3 I had a lot of empty space available on. Maybe clone requires and entire hdd volume to boot?

To clarify about the other thing. When I moved from Mavericks to Sierra, I bought some new externals at the same time, They would format. However I'm a bit OCD and would redo the formatting a second time... just to make sure it 'caught', lol.... and that's when formatting would fail. Which of course drove me crazy because that's not supposed to happen... and has never happened. You should be able to format repeatedly over and over one right after the other if one so desired and not get any error or failure.

So I looked for this particular issue and apparently it was a 'thing'. The solution was to use windows disk manager to get rid of whatever that little disk01 EFI thing that gets put on it when its formatted with the FAT32 from the factory. I do understand any OS disk formatting puts its own EFI thing onto the drive. Apparently its the windows pre-formatting that was a problem though.

Now this particular 6tb I partitioned to put the test on.... I don't remember if it was one I formatted when I was using Mavericks or whether I had done the bit with it on my windows machine and then formatted under the Sierra OS.

I realize this is all long winded and complicated but I'm just trying to figure what could possibly be the reason my external won't boot when it damn well should, lol

Be that as it may, I am successfully running off the High Sierra test partition I made on my Mac hdd. Nonetheless the non booting external clone issue is something I'd like to get to the bottom of.

 

Last edited: Oct 17, 2019

Oops missed yours. GUID journaled as usual

 

Perhaps there's a problem with your EFI (or ESP) partition. The only way to get rid of that is (only if you have nothing important left on this Hard Disk) to erase the EFI partition, and to reformat, but this time only with the official apple Disk Utility (/Applications/Utilities/Disk Utility).

To erase the EFI Partition I use Paragon Hard Disk Manager, with it you can visualize this very little part (around 200 - 500 Mo only) at the beginning of your drive, click on it and choose delete partition. You have then to "Apply changes" and confirm. Once erased, just to be sure, I'd delete the other partitions too (only if you're absolutely sure that there is nothing important on it!), so that your drive become completely blank, un-formated.

Apply the changes and confirm again, quit, then try to reformat normally (choose "HFS+ journalised" as file system) with Disk Utility.

Then you could try to clone your system again (personnally, I recommend CCC, I use it every day for my backup needs, never had a single problem), don't forget to set your clone bootable, now try to boot from your new clone (hit and maintain option key at bootup, then choose the right disk), it should work.

CCC have an interesting function: when you clone your system it reminds you to clone your Recovery partition too, I recommend to do it, we never know...

 

Thanks. Something to look into.

Now things gotten a bit stranger. I have another drive that I put my clones onto and update every once in a while when there's any major changes to my system. I have two clones on there. One is my main system, currently Sierra, and another I have Mavericks one so I can still use Photoshop C6 and Lightroom (adobe can piss off with their subscription scam, lol).

Just to see, I just went and connected that drive and was able to boot off of those clones! The Mavericks booted up fine. However.... when I selected the Sierra clone to boot from, about halfway though the bootup, it switched over to boot from the Mac's hdd. I could actually see this happen because I have 2 monitors and, depending on various circumstances, the startup progress bar will appear on either one of the monitors.
In this case the progress bar was on the right one, then halfway through it switched to the left monitor, so I knew something happened. I'm thinking that since the clone and the mac hdd system are identical, the machine must've defaulted over to its internal system preferably.

While I was at it making a High Sierra test clone on the 6tb external at issue with, I also decided to make backup clones of my clones.
So currently I have the HS test clone, the Sierra clone and the Mavericks clone on there. None of them will let me boot up either. Something specific to that drive then? Hmmmmm

Can't be a partition thing because my main clone copies that work each reside on partitions.

I use Diskwarrior as well. It says the 6tb drive is optimum.

If I wanted to spend time experimenting further, I could reformat the 6tb using disk utility from the HS Sierra test system on the macs internal drive which works. If that doesn't let the drive boot, I could then try disk utility from the Mavericks OS. It'd be a time consuming experiment so I'd think about it or just let things be as they are.
I'm sure there is nothing wrong with the actual clones themselves. Just can't boot with them for some reason.

 

Last edited: Oct 17, 2019

Dug up an unused bare 3tb Hitachi drive. Stuck it into my OWC usb3 dock and cloned onto it. Wouldn't boot.

I downloaded CCC for a free trial. Doing a clone now. Will see if that'll boot.

 

yes exactly - actually I always try booting the backup before performing any upgrades on the system drive later;
one thing to be aware of though - older Macs receive firmware upgrade as initial step of MacOS upgrade, so obviously let's say if you have a newer OS on external drive and want to boot on older Mac (with older firmware), it will NOT boot, despite the hardware is fully compatible

 

Update for those wondering if it is safe to upgrade.

After trying to update to Mojave & not easily finding the 10.14 ISO, I decided to just install Catalina.

The install process started automatically after downloading & took 30 minutes or so.

Everything working fine. The new OS is slightly different & requires apps to give new permissions for access at first launch.

Dark theme works great for the lack-luster screens on these models.

 

I can highly recommend dosdude1's "Patcher" utilities, which can also serve to download and create genuine MacOS installers from AppStore without making any patching changes to MacOS itself:
http://dosdude1.com/software.html

 

Well how do ya like that.. As I say, I cloned system onto this other drive with Superduper. Usual story, It wouldn't boot. Doesn't show up as an option on startup either. D/l'd CCC. Made a clone onto the same drive. Appears as option. It booted up!

Not only that. Earlier when I said I was able to boot from another drive I have that I use as my primary clone drive, I could boot from that oddly enough. However I did say that while booting from the clone of the same system that's on the Mac hdd, in mid boot the computer switched over to continue booting from the Mac system itself.

The CCC clone I didn't do that. I'm gonna redo all my clones with CCC.

Interesting. Never thought of that one, thanks.