Bootup from external SSD?

iBaba

macrumors member
Original poster
Jul 10, 2018
52
6
Is it possible to have a separate system that runs completely from an external SSD drive and make it work all from that drive but also have the option to have the computer run from it's internal drive when the SSD is not plugged in. Like two completely different systems where all Apps, settings, etc are kept completely separately?

So you can startup the machine normally or plug in the SSD drive and ru it from there but as a totally different computer.

This should be possible right?
 

maflynn

Moderator
Staff member
May 3, 2009
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Boston
s it possible to have a separate system that runs completely from an external SSD
Yup, I ran that way for years.

but also have the option to have the computer run from it's internal drive when the SSD is not plugged in
Possible, but you'll have two home folders and things could get messy that way. When I had done it, my internal drive was set for data (held my lightroom library), the OS and home folder were on the SSD.
 

iBaba

macrumors member
Original poster
Jul 10, 2018
52
6
Yup, I ran that way for years.


Possible, but you'll have two home folders and things could get messy that way. When I had done it, my internal drive was set for data (held my lightroom library), the OS and home folder were on the SSD.
Thanks for the fast reply. But if it's on 2 separate drives then the home folders should never interfere with each other right?
 

maflynn

Moderator
Staff member
May 3, 2009
66,686
33,573
Boston
Thanks for the fast reply. But if it's on 2 separate drives then the home folders should never interfere with each other right?
Interfere no, but by default you'll have two home folders and with that, you run the risk of duplicated files and/or conflicts.
Program A. sets values in ~/Library when you booted up from the SSD. You then boot up from the internal drive and start using Program A, but the value in the ~/Library is missing so it starts behaving oddly and you have no idea why. Maybe that's not a real world example, but its what came to my mind.
 

iBaba

macrumors member
Original poster
Jul 10, 2018
52
6
Right. That makes sense.

Ill have to see indeed if that becomes a problem. Is very likely can.

I wonder if there’s a way to disable the internal drive or part of it? Maybe put the system on a partition in the internal HD and encrypt it so it need a password to function?
 

Fishrrman

macrumors Core
Feb 20, 2009
19,439
6,736
OP:

What you want to do is child's play on the Mac.
Yes, you should keep the home folders separate.
 

iBaba

macrumors member
Original poster
Jul 10, 2018
52
6
Probably going with this drive as a bootup SSD:

https://www.amazon.com/SanDisk-500G...3&keywords=SanDisk+500GB+Extreme+Portable+SSD

Question though, if this becomes a Mac boot up drive can I besides the system also store other files on it and use it as a sharing drive? Or would I make a partition in that case?

PS: Any better options available to buy?
[doublepost=1539225369][/doublepost]
OP:

What you want to do is child's play on the Mac.
Yes, you should keep the home folders separate.
Keeping the Home folders separate and preventing issues. What's the best approach to this or what is your experience in dealing with this?
 

Lyn2012

macrumors 6502a
Dec 26, 2007
624
234
I'm joining this thread because I have a question regarding boot up from an external HDD. My external hard drive is partitioned, one partition has a bootable backup (using SuperDuper) of my iMac. How can I boot from this external drive partition, it doesn't seem to offer me the correct option, I'm only able to select the external drive as a whole, not the specific partition. Am I trying to do the impossible, or is there a way round this?

TIA.
 

Porkchop Sandwich

macrumors regular
Feb 3, 2017
243
141
Timely thread. I hope it's okay to chime-in w/a related question iBaba, I've been considering doing just what you describe. I currently have a bootable copy of HS on an external. Installation and s/u went good and smooth. iBaba, it's literally just like a completely different computer running it this way.

I have two questions that may contribute to this thread:

1. I would ass-ume that the system running off the external can be backed-up in time machine just like normal, yes? Anything special to consider other than perhaps using a single dedicated drive for the tm backups? (i.e., a dedicated bu drive for each 'computer')

2. Using folder permissions to allow access, is there a way to make your internal hard drive accessible to the 'computer' you're using from the external?

Sorry if these are noob q's, I just don't know the answers??

..btw, maflynn: You said you ran this way for yrs which seems to imply that you no longer do. Was there a particular reason you stopped? Just too redundant perhaps?
 

Fishrrman

macrumors Core
Feb 20, 2009
19,439
6,736
"What's the best approach to this or what is your experience in dealing with this?"

Sitting here on my desk, right now, I have no less than 7 bootable drives/partitions
(this doesn't include -other- bootable drives scattered around elsewhere).
A few of these are "cloned backups" created with CarbonCopyCloner, so of course they are "copies of" my main drive.

But I really just let each one "be it's own drive", so to speak.
I don't bother with trying to "synch" home folders, or anything, for that matter.

Works fine for me.

TIP:
I -do- have "a main drive" -- the one that I normally boot from and work from.
That one I'm more particular about keeping "in shape".

But "the others"?
I don't worry about 'em!
 
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