Specs for Bootable USB drive?

[Ambrosia7177]

I would like to buy some more USB thumb-drives in order to make myself the following...

1.) Bootable USB w macOS Sierra
2.) Bootable USB w macOS High Sierra
3.) Bootable USB w macOS Mojave


What specs will I need in order to place one OS on each drive, and make it not only bootable, but functional (i.e. fast enough to be usable)?

I think I need to get USB 3, and am thinking I probably need 32 GB, but I don't keep up with consumer technology!

Thanks as always.

 

[DeltaMac]

I would like to buy some more USB thumb-drives in order to make myself the following...

1.) Bootable USB w macOS Sierra
2.) Bootable USB w macOS High Sierra
3.) Bootable USB w macOS Mojave


What specs will I need in order to place one OS on each drive, and make it not only bootable, but functional (i.e. fast enough to be usable)?

I think I need to get USB 3, and am thinking I probably need 32 GB, but I don't keep up with consumer technology!

Thanks as always.

There's multiple possible methods for you to use.
Each of those macOS installers will fit on an 8GB flash drive. I have a small box filled with a couple dozen 8GB drives, with most setup as installer drives, every macOS system from Leopard to Mojave. As 8GB USB drives are getting harder to find now, 16GB for each is very usable. You could even make 3 partitions on a 32GB drive, and create bootable installers for each of the systems that you want, all on the same device.
The actual advertised USB speed (USB 2.0 or USB 3.0) is not terribly important, as long as the drive is bootable (test it after you make it). Some USB flash drives can be really slow to write (you need patience waiting for some drives to finish copying files for this), but as long as they work (and boot your Mac), that's a usable installer. The fastest installer set that I have is on an external enclosure (USB 3.1), with a small SSD. You can find decent (non-plastic) cases for less than $20, and cheap SSD (120GB for less than $20, or 240GB for less than $30), which can have multiple partitions. The one that I use has partitions for Leopard to Mojave installers, and enough space left to make backups of (small) customer drives. The copy process for any installer completes within 2 or 3 minutes, then you are subject to whatever the write speed is on the Mac's boot drive (the installer app is done at that point). The external SSD that I described is what I recommend for that.... but I also have individual installers on flash drives. I do use both.
finally - I bought a 64GB USB flash drive for about $15 last December. That one also has a multiple partition setup with the systems that I most commonly install: Lion, Yosemite, El Capitan, High Sierra, and Mojave. Works great, and is in my pocket most days

 

[Mr_Brightside_@]

I've used a multitude of different drives. Wipe them to macOS Extended Journaled and you're good.
Get a handful of 8 GB usb 3 drives and keep them separate. Mine are all together on one usb and ejecting it is a pain.

 

[Ambrosia7177]

Each of those macOS installers will fit on an 8GB flash drive.

I own a few of these and they have served me well...

https://www.outletpc.com/uv7677-cor...MI1bS83J_a4AIVD5IYCh0GbwTuEAkYBSABEgICJvD_BwE

Sounds like I can buy some more and they should work just fine.

I have a small box filled with a couple dozen 8GB drives, with most setup as installer drives, every macOS system from Leopard to Mojave.

I'm jealous!! (Wish I would have know how to do this years ago!)

As 8GB USB drives are getting harder to find now, 16GB for each is very usable. You could even make 3 partitions on a 32GB drive, and create bootable installers for each of the systems that you want, all on the same device.

finally - I bought a 64GB USB flash drive for about $15 last December. That one also has a multiple partition setup with the systems that I most commonly install: Lion, Yosemite, El Capitan, High Sierra, and Mojave. Works great, and is in my pocket most days

So I just go into "Disk Utility" and choose 3 partitions and I could accomplish what you say above?

Which file format do I choose?
[doublepost=1551213670][/doublepost]

I've used a multitude of different drives. Wipe them to macOS Extended Journaled and you're good.
Get a handful of 8 GB usb 3 drives and keep them separate. Mine are all together on one usb and ejecting it is a pain.

Yeah, I tend to like to segregate stuff.

Less is more! ;-)

I am going to buy 6 of these...

https://www.outletpc.com/uv7677-cor...MI1bS83J_a4AIVD5IYCh0GbwTuEAkYBSABEgICJvD_BwE

And make two copies of Sierra, High Sierra (still have to finish my "homework assignment" from last night @Mr_Brightside_@), and Mojave.

Then I will store one at home, one out-of-state in storage, plus I'll save all 3 OS's on maybe two external drives and keep one with me and one out-of-state and then the issue I had with my copy of High Sierra getting trashed shouldn't happen again!!

 

[Mr_Brightside_@]

You should be fine partitioning those 64 GB ones into eight 8 GB partitions, if you so choose. But 3 partitions is fine too.

 

[Erehy Dobon]

.

 

[MBAir2010]

There are every osx on a externa hd from lion to highest sierra on and a time machne copy from snow leopard which boots and recovers much faster than a usb. If i need to re-install an osx , i will place that osx on an blank usb if neeeed instead of 8 separate ones.
I gets a cookie for this osx preparness!

 

[Fishrrman]

I'd suggest USB3 flash drives, 16gb.

Beyond that, nothing special is needed.

I would suggest using DiskMaker X to create the bootable flashdrives -- fast and easy and no messing with the terminal.

As mentioned above, you could also use SD cards (again, 16gb) and an SD card reader (if the Mac in question doesn't have an SD slot).