I can copy El Capitan installation on thumb drive but it is not visible when I hold option key on restart
I am using OS X El Capitan on Macbook 7.1 (Mid-2010). My thumbdrive is detected inside El Capitan and I can make it bootable and put El Capitan installation on it by using terminal command:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app --nointeraction
but thumb drive is not visible when I hold option on restart. Therefore I can't install El Capitan on my new SSD that I have. When I install using terminal, I get this message at the end of the process, in terminal:
Couldn't mount dmg /Volumes/Install OS X El Capitan/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg (error code 112)Mount of outer dmg failed.
After this, when I ran the hdiutil:
hdiutil verify Install\ OS\ X\ El\ Capitan.app/Contents/SharedSupport/InstallESD.dmg
on the thumb drive, I got:
Checksumming Protective Master Boot Record (MBR : 0)… Protective Master Boot Record (MBR :: checksum failed with error 1000. ............................................................................................................................................................... calculated CRC32 $00000000, expected CRC32 $BE5D6293 hdiutil: verify: checksum of "Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg" is INVALID hdiutil: verify failed - image data corrupted
So the error can be either on the installation or the thumb drive itself (bad drive).
Sometimes I get this message at the end of the installation thumbdrive making process:
Failed to copy kernelcache, The file “kernelcache” couldn’t be opened because there is no such file.
I want to install fresh clean install of El Capitan on my brand new SSD that I bought, and somehow Apple is preventing me from using it. Any help anyone?
- (Download the latest El Capitan Installer (10.11.3))
-
Open Terminal and check the hash of InstallESD.dmg:
shasum /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/SharedSupport/InstallESD.dmgThe result (as of March, 5th 2016) should be: 526a6f7a619ef86f42acc026276aab351ea27614
- Insert your thumb drive
-
Get the disk identifier of the thumb drive with
diskutil listBelow I assume the disk identifier of the thumb drive is disk1
-
Delete any MBR on the thumb drive:
diskutil umountDisk /dev/disk1 sudo dd if=/dev/zero of=/dev/disk1 bs=512 count=1 diskutil mountDisk /dev/disk1 -
Open Disk Utility and partition the thumb drive:
Options...: GUID partition table
Name: Untitled
Format: Mac OS X Extended (Journaled) -
Create the El Capitan Installer thumb drive:
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app --nointeractionThe output looks like this:
Erasing Disk: 0%... 10%... 20%... 30%...100%... Copying installer files to disk... Copy complete. Making disk bootable... Copying boot files... Copy complete. Done. -
Check the InstallESD.dmg on the thumb drive:
hdiutil verify /Volumes/Install\ OS\ X\ El\ Capitan/Install\ OS\ X\ El\ Capitan.app/Contents/SharedSupport/InstallESD.dmgThe output should look like this:
Checksumming Protective Master Boot Record (MBR : 0)… Protective Master Boot Record (MBR :: verified CRC32 $8A0AD7CD Checksumming GPT Header (Primary GPT Header : 1)… GPT Header (Primary GPT Header : 1): verified CRC32 $E61CC7FE Checksumming GPT Partition Data (Primary GPT Table : 2)… GPT Partition Data (Primary GPT Tabl: verified CRC32 $8F9F9AF5 Checksumming (Apple_Free : 3)… (Apple_Free : 3): verified CRC32 $00000000 Checksumming EFI System Partition (C12A7328-F81F-11D2-BA4B-00A0C93EC93B : 4)… .... EFI System Partition (C12A7328-F81F-: verified CRC32 $B54B659C Checksumming disk image (Apple_HFS : 5)… ................................................................................................................................. disk image (Apple_HFS : 5): verified CRC32 $F1A0F123 Checksumming (Apple_Free : 6)… ................................................................................................................................... (Apple_Free : 6): verified CRC32 $00000000 Checksumming GPT Partition Data (Backup GPT Table : 7)… ................................................................................................................................... GPT Partition Data (Backup GPT Table: verified CRC32 $8F9F9AF5 Checksumming GPT Header (Backup GPT Header : 8)… .................................................................................................................................... GPT Header (Backup GPT Header : 8): verified CRC32 $5826D5C7 .................................................................................................................................... verified CRC32 $BE5D6293 hdiutil: verify: checksum of "/Volumes/Install OS X El Capitan/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg" is VALIDSome of the CRC32 values may be different in your output!
Reboot you Mac with the thumb drive attached and hold the alt/opt button. If the thumb drive doesn't show up on the first run just repeat the step. It took me 2 tries to successfully boot to the installer thumb drive.
As a workaround, you can mount the SSD in an external enclosure, run the Install OSX app on a working computer, and point it to the external device. Afterwards, you should then be able to remove the drive from the enclosure and swap it in to your computer.