Downgrade to Yosemite with an El Capitan backup

Hi,

To answer your questions first:

• A backup made in 10.11 won't be recognised by 10.10 - it works the other way around because 10.11 is aware of all the intricacies of 10.10 and so knows what to do with a 10.10 backup. 10.10 isn't aware of 10.11's intricacies and that's why it won't work.
• Are you 100% certain that the Yosemite installer isn't sitting in your Applications folder? The App Store doesn't tell you that this is where it puts the installer.

Max.

Hello Max

Thank you for this. It struck a chord and I thought it would work.

However on your step 4 is says "Re-install a new copy of OSX" and when I try to install Mountain Lion (10.8) on "MacIntosh HD" I get the error message "You can't upgrade this version of OSX because a newer version is installed". So it looks like this process (at least on my computer) is designed to install an upgrade rather than fall back.

Am I doing something wrong? Is there some step I have missed, a different thing I could try or is this a roadblock?

Many thanks for your support.

Also, this will erase that partition I presume so for any who migrated content...this is not a good option?

It won't erase the partition - you have to do that intentionally from Disk Utilities if you want to do it.

I'm feeling something has gone missing here. I thought your append had a list of things to do ... ? and I was planning on carefully trying again but no dice ...

I do have the Yosemite install appplication in my Applications folder so (in theory) I just need to the point when I can install it off 10.8.

No, it's a roadblock. I made this work on a system running Beta 1 to get it back to Yosemite, but it was following a bad install (either the capability has been removed again or that install was deficient enough not to be recognised as El Capitan).

So in your case there is no easy solution - just a couple of hacky ones. If you want to embark on one, I would encourage you to first make a backup with Time Machine and one with a 3rd party backup solution as well (because even Time Machine has some bugs on the latest beta).

Like that you can always get back to where you are now.

I replied to your earlier post at the same time you posted this one.

I removed the instructions above since, after reading your post, I re-tried it for myself and confirmed that they won't work.

Thanks Max.

Guess I'll have to live with it until El Capitan goes to production and the bugs I am experiencing are fixed.

Thanks for your help.

Hi msjhaffey, if your downgrade doesn't succes, you may try this :

You'll need to make a Yosemite USB installer of at least 8GB. (a USB3 one will be much quicker).

First download the OS X 10.10 Yosemite installer from the Mac App Store in the Purchases section (you may need to hold alt/option while selecting Purchases. Once it's downloaded, just quit the installer and set the downloaded file's name to InstallOSXYosemite.app (make sure only .app, not .app.app)

• Plug in your USB drive into the computer and open Disk Utility (in Applications).
• Select the USB drive from the left sidebar and click on Erase tab.
• Choose Mac OS Extended (Journaled) in the format box and set the name be YosemiteInstaller
• Now click on Erase button and wait until the format process completes.
• Then choose Partition tab and select 1 Partition from Partition Layout dropdown menu. Click on Option and ensure GUID Partition Table is selected as the partition scheme, with its name set to YosemiteInstaller.
• Launch the Terminalapp (in Applications/Utilities) and copy-paste the following command in, and then hit Enter:

  sudo /Applications/InstallOSXYosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/YosemiteInstaller --applicationpath /Applications/InstallOSXYosemite.app --nointeraction

• This will create the bootable USB flash drive. This takes between 10-20 minutes. Do not interrupt the Terminal or eject the flash drive during the process. Once the process completes, you will see the message "Copy Complete. Done."

The OS X Yosemite bootable USB flash drive will be ready for use and you can start the clean installation process.How to Clean Install OS X Yosemite on Your Mac

• Ensure the bootable USB flash drive is plugged into your Mac and restart the computer. As soon as the start-up chime plays, press the Option key (Alt).
• Choose the USB drive on the start-up drive selection screen and hit Enter/Return on the keyboard.
• Wait until the Yosemite installer appears on screen. This could take a few seconds or minutes.
• Click on Disk Utility and then hit Continue.
• Click on Macintosh HD from the left hand-side pane and then hit Erase tab on the top-right portion of the window. Leave all the settings at their default values and then hit Erase button at the bottom right. This will wipe all files stored on your startup hard drive.
• When the erasing process is complete, return to the first screen where you selected Disk Utility. Now click on Install OS X and then hit Continue.
• Choose the Macintosh HD partition you erased in step 5 and then click Install.

Hi Habil,

You've just copy-pasted my reply to someone else's problem to this thread, which would be fine except that it doesn't apply here - msjhaffey doesn't want a clean install of Yosemite because he doesn't have a Yosemite backup.

Max.

Thanks, Habil.

However, my main problem is that I have data on my MacIntosh HD that I didn't previously back up so I don't want to erase it and the Time Machine backups of EL Capitan aren't compatible with Yosemite.

Thanks again.

Hi Max,

Yes it is, just for fair use and helping each other,

Unfortunately if you want to downgrade without Time Machine you have to back it up or your data loss.

If you running windows you can open the Harddisk and back it up at another pc,

You may go to AASP or someone who understand about this because if you want to downgrade without timemachine and no backup your data will loss.

Hello Max (if you're still watching this thread)

Does the new El Capitan Recovery Update change things? Might I be able to recover using this?

If so, please will you re-post your list of steps to take? In particular there was a step involving holding down a key after re-booting but I can't recall the key.

Many thanks

Hi, 🙂

The new Recovery Update won't help you get back to Yosemite with your data intact unfortunately. The latest 10.11 beta is pretty stable now though. And you might find that some of the software you need works after you disable the El Capitan's new security feature that is responsible for quite a lot of software not working. To do that, boot into Recovery Mode (cmd+R while booting). Then go to the Utilities menu at the top of the screen and open Terminal. Type the following into the Terminal window:

/usr/bin/csrutil disable

And reboot normally.