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applelover4u

macrumors 6502
Original poster
Nov 6, 2012
336
179
I bought from external drive

My external start up disk use to work but now every external drive or USB drive or sd card I insert into my Mac I will get the message " disk is unreadable " with the option to ignore, eject or initialize which doesn't work

I do get the same problem on my other Mac OS X installation as well When I insert sd cards USB drives or external drives

It use to be that the external start up disk would work and it would be any other thing I plugged in and would get that message but now it includes my startup disk

I tried sd card port and all USB ports

This is frustrating
 
Last edited:
Do the disks appear in disk utility? Have you tested if they work with a diffrent OS loaded?

Also it would be nice to know:
  • What Mac you use (model, year, screen size).
  • What version of macOS / Mac Os X you use.
 
Do the disks appear in disk utility? Have you tested if they work with a diffrent OS loaded?

Also it would be nice to know:
  • What Mac you use (model, year, screen size).
  • What version of macOS / Mac Os X you use.

Ok I got it working somewhat. My main external drive had the circle with slash through it when booting up.

I used disk warrior to fix it and it did except now my OS X isn't like bootable because of what diskwarrior did? Guess I'm confused it was called startup disk but now it's called untitled and when I click on the drive and it have recovery folders and a volume folder that contains my startup drive and OS X so I'm trying to figure what to do next

I have a Mac mini late 2014 newest osx
 
What is your "newest osx" version number?
If you have 10.12.5 (the most recent update), then that is not called "osx", but is called macOS.
I assume that's what you mean, but if you DO have OS X, then you are not on the newest... :D

That being said, boot to your recovery system (restart, holding Command + r), then reinstall macOS, choosing your external USB as the destination for the install. That will not erase anything, but will make your external bootable again, if that's what you want.
 
That being said, boot to your recovery system (restart, holding Command + r), then reinstall macOS, choosing your external USB as the destination for the install. That will not erase anything, but will make your external bootable again, if that's what you want.

Also remember to backup any important data if you need to wipe out the drive. Can be done by booting another OS from an external source.
 
What is your "newest osx" version number?
If you have 10.12.5 (the most recent update), then that is not called "osx", but is called macOS.
I assume that's what you mean, but if you DO have OS X, then you are not on the newest... :D

That being said, boot to your recovery system (restart, holding Command + r), then reinstall macOS, choosing your external USB as the destination for the install. That will not erase anything, but will make your external bootable again, if that's what you want.

Lol as I stated it won't read drives/ mount or whatever. So can't even reinstall then

I used disk warrior and it repaired it good enough so that I could get my data off the drive then I reinstalled macOS. Now I got to
Copy everything back over

And for now I'm using CC for backups!! I almost cried when I thought all my data would be lost
 
It sounds like the internal drive got corrupted -- something went wrong with the System and it wouldn't boot.
If the boot drive won't work, you're not getting any other drives to mount (except a second, external boot drive).

There's nothing wrong with using CCC for backups, I recommend it instead of Time Machine for ALL users.

Something to try:
a. shut down (all the way off)
b. connect your CCC backup
c. press power-on button and IMMEDIATELY hold down the option key and keep holding it down.
d. does the "startup manager" appear?
e. if so, select the EXTERNAL boot drive and hit return
f. what happens next?
 
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