Cannot create bootable El Capitan USB media using "createinstallmedia" or Diskmaker X

martin from wrote:

I do not understand what you mean by, " install El Capitan on the flash drive and then add El Cap Installer to its application folder?" El Capitan itself surely is a very large file and is not going to fit on a flash drive?...

Flash drives are available with capacities up to 256GB, which should be plenty of room. I put three bootable partitions (10.8, 10.9, and 10.10) and a non-bootable storage partition on a single 128GB Flash drive and each had a Yosemite installer available along with other disk maintenance programs. That proved very useful when I had to work on an unbootable 2011 MBP. Best Buy is selling 32GB Flash drives for $9 and Office Depot has them for $11.

I actually just prefer bootable clones - they can be on any external media as long as it's formatted correctly and you can boot from them, erase your hard drive, and clone back the system very quickly without much effort. I maintain one "factory fresh" clone as well as two regularly updated clones of each OS version that I am either running or has been on my machines (that would be 10.9, 10.9, 10.10, and 10.11) on separate external hard drive partitions. For me, just an OS install wouldn't be all that helpful without my apps, preferences, etc. etc.

Ok that's helpful. Thanks

How do I make a bootable clone? Can I do this on my external drive for e.g. that I have my back-ups on or, does it have to be on something else and if so what please?

A bootable clone needs to be on its own partition - whether that is on a partition on a larger external drive or on a separate drive is completely up to you (besides, Time Machine should have its own space or it might mess with other files there). It needs to be formatted Mac OS X Extended (Journaled) and GUID partition scheme to be bootable. Unlike Time Machine, the size needs to be about your hard drive's used space - except add quite a few GB to make sure you're covered for when you add files to your internal and then update the clone. My current internal system is about 135 GB and my clones' partition sizes are about 200 - 300 GB.

So, once you have a formatted partition or drive, plug it in, launch either CarbonCopyCloner or SuperDuper and tell them to clone to your drive. It helps to name it e.g. Mac HD Yosemite clone1. After that, let it do its thing - first clone takes a while. When finished, I test it by going to System Preferences > Startup Disk and choose the new clone to restart. After it boots successfully and you try a couple of files or an app, boot back into your internal and you're done. SuperDuper is free for basic full clone backups; CCC costs a little, but it can also create a recovery partition on your clone partition.

Thanks for this information. Appreciated.

I prefer bootable clones too, for backup and as a resource just as Time Machine is. Large externals with multiple partitions allow rotating dated backups to keep multiple versions.They're also better than TM for virtual machine files.

But for simple and portable troubleshooting and upgrades, the little bootable Flash drives can come in very handy.

Hi Kappy

All worked as you said in the end. I had bought a SanDisk Cruzer Blade on eBay and it malfunction eventually in my trials and tribulations trying to make a bootable drive, the company replaced it and same happened. Took it up with SanDisk and they were fakes so, bought a Toshiba TransMemory Stick and this time everything went as planned from erasing through to Terminal command and when I restart with Option key depressed it shows up the bootable drive in the choices. It doesn't show in System Preferences 'start disk' but that is irrelevant as, I now have a bootable drive. Thanks to a few others on this topic as well as, it kept me working at it even though I originally had duff memory sticks. 🙂

Following your example, I got it working with an El Capitan version downloaded on 10/21 from the App store. Reboot with Option key, then insert USB flash drive when volume selector screen appears and from there it is easy. Thanks for the research and tip, EdisonW.

I found that (as Kappy said) that it works whether you have the bootable drive already inserted or added afterwards when you start your computer with Alt key depressed.

I just tried to make a bootable installer thumb drive with the latest software, 10.11.1 and ran into similar problems. I also made a bootable external USB HD with a clean 10.11.1 installation to test as well. To summarize, which all took place on a late 2012 27" iMac:

1. Booting with the Option key pressed to bring up the boot drive selection screen at first produced inconsistent results. The internal HD was always present, but the external drives sometimes appeared and sometimes didn't. I then discovered that all USB ports are not created equal!!!! A device plugged into the USB port next to the SD card slot was not recognized, but plugging the ext HD and/or the thumbdrive into any of the other 3 USB ports worked! I also tried my Logitech Unifying Receiver in the suspect slot and it failed to work as well.
2. In System Preferences/Startup Disk the USB HD appears just fine, but the USB thumbdrive does not. Both drives mount properly. It doesn't matter what USB port you use. All four USB ports work otherwise.

Conclusion: We have two problems, a bug in the boot time USB drivers, and a bug in System Preferences/Startup disk.

Interesting. I'll have a look when I have time to see if my USB ports are the same as yours.

Re the "System Preference Startup Disk" I do not understand why anybody would expect to find it there as, a bootable drive is for use when your system has failed and therefore, unless i'm missing something, you would be starting your Mac with Start whilst depressing Alt, in order to see the options to get going again whereas System Preference Start up Disk is not available when your system has failed, which is surely why one wants a bootable drive in the first place?

I FOUND THE SOLUTION! If you guys are having this issue it's because the system reverts to a previous state whichever is in its memory from pre-ElCapitan times.

If you want to get rid of this it's really simple:

• On the recovery screen click on the Utilities tab -> terminal.
• From the terminal type date. Press return key, and The date will printed. More than likely the system's date is going to show some year which is not reality, mine showed that it was in the year 2000. We want to change the date.
• Type the date in the following format: MMDDtimein24hrformatYY
• So if it was 5:30PM (17:30) on November 10, 2015, you would enter the following into the terminal:

  date 1110173015

• Press the return key. Now the date will be changed to whatever you entered manually.
• Click Terminal -> Quit.
• Now you'll be back on the recovery screen and you can install the OS X without issues 🙂

I FOUND THE SOLUTION! If you guys are having this issue it's because the system reverts to a previous state whichever is in its memory from pre-ElCapitan times.

If you want to get rid of this it's really simple:

• On the recovery screen click on the Utilities tab -> terminal.
• From the terminal type date. Press return key, and The date will printed. More than likely the system's date is going to show some year which is not reality, mine showed that it was in the year 2000. We want to change the date.
• Type the date in the following format: MMDDtimein24hrformatYY
• So if it was 5:30PM (17:30) on November 10, 2015, you would enter the following into the terminal:

  date 1110173015

• Press the return key. Now the date will be changed to whatever you entered manually.
• Click Terminal -> Quit.
• Now you'll be back on the recovery screen and you can install the OS X without issues

Thank you so much EdisonW, I was about to throw my Kingston key out the window 🙂