Want to highlight a helpful answer? Upvote!
Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >
Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >
I tried installing mountain lion onto an external SSD drive. At first it worked, using my USB install drive and selected my external drive as the target. All the files are copied over and asked me to restart. However, after restart all it did is booted back into my internal drive OSX. Even if I held down the option button it won't allow me to boot the external drive. Any ideas? I'm doing this from the retina macbook pro.
Do you see the boot menu at startup when you hold the Option key? Do you have a firmware password set up on the system? Finally, what kind of Mac do you have and are you using a Bluetooth keyboard? If your keyboard is wireless, then hold the Option key immediately after you hear the boot chimes when restarting, and not before.
I see the boot menu. My options are my internal drive, bootcamp drive and OSX recovery. Not the external one.
I don't have a firmware password.
I'm using the retina macbook pro. Not bluetooth keyboard.
How is the SSD connected to the system (USB, Firewire, Thunderbolt), and do you have an alternative drive enclosure you can try?
It's connected via thunderbolt. It's the lacie big5 drive. I don't have another enclouser to test with. It's a raided 0 setup between 5 drives.
Verify that your external was formatted as a GUID drive.
Install or Reinstall Lion/Mountain Lion from Scratch
Be sure you backup your files to an external drive or second internal drive because the following procedure will remove everything from the hard drive.
Boot to the Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Partition and Format the hard drive:
1. Select Disk Utility from the main menu and click on the Continue button.
2. After DU loads select your external hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
Reinstall Lion/Mountain Lion: Select the External drive, then select Install Lion/Mountain Lion and click on the Install button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible
because it is three times faster than wireless.
The RAID setup might be the issue here. Try destroying the RAID and rebuilding it, and then partitioning/formatting and reinstalling OS X to it again.
Yep that did it. Destoryed the raid and installed only one of the five drives. Worked. I don't know how I can make it work with the raid, I've tried reformating and rebuilding the raids same result. But that's ok since this is testing only for me. Unfortunately it won't be helpful for the next guy.
There might be some detailed issue with block size requirements for the RAID. Have you tried both 4K and 512-byte block sizes, and any other customizations that Lacie offers?
Actually now I have another boot problem. Originally I was thinking that I could install OSX to the external drive from my rMBP and then boot it with my iMac (because iMac won't let me install ML, because the iMac came with ML preinstalled). But now I found out that when I try to boot the drive with the iMac it just gives a stop sign on the screen and then shutdown. How do I boot the iMac with an external drive?
I have the newest iMac model.
Odd, a fully updated OS should boot to most new hardware. Can you boot the system to this drive even in Safe Mode, or to the Recovery HD partition on it? Try installing OS X on the external drive from the iMac, and then see if you can boot to the drive on both systems.
The problem is that iMac won't let me install ML on external drive. As soon as I run the installer, it gives me an warning message saying that this mac can't install it I think it's because the mac came preinstalled with ML.
I will try safe mode tonight when I get home.
The problem here depends on when the respective Macs were issued. If the iMac was shipped with Mountain Lion, then it will likely have been shipped with version 10.8.1 or later. If you install version 10.8.0 on the external drive then this version will be less than that which supports the iMac, and may result in the inability to boot.
Even if the versions are the same (ie, 10.8.3), there may be slight build differences that prevent one from booting the other. In these cases, you may need to wait until OS X 10.8.4 comes out for the boot drive to support both systems.
So I should at least give it a shot? Update the external drive system to 10.8.3 and then try again? I should have a better chance then?
That would be my recommendation.
External drive won't boot after install?
