Installing Yosemite failed

Hello!

If the computer doesn't boot with [cmd] + [r] there might be something wrong with the hdd after all. Unless your Mac currently is running Snow Leopard or something earlier.

In any case, please try this:

. It will take you about 15 minutes or less to do these, depending on how bad the problem on your Mac is.

The goal here is to boot your Mac to the so-called Single User mode where you’ll have a chance to repair the disk. This might solve your issue and even if it doesn’t- it’s still a decent maintenance step to perform. These steps won’t erase your data or reinstall your Mac in any way.

Here’s how:

1/ Make sure your computer is completely shut down.

2/ You’ll have to be quick next: Press the Mac’s power button. As soon as you either hear the loud chime, or see the display light up - usually after a second or 2 - on your keyboard press [cmd] + [s] Keep these keys on your keyboard pressed until you see a very old-fashioned looking black screen with white text scrolling. At the bottom you will see something akin to “root #”

Type the line below after the # and press return:

/sbin/fsck -fy

Your Mac will now check your drive for errors and if it finds any it will attempt to automatically repair them. Once it displays “root #” again it has finished. Read back what the results were. If it says “repair successful” or something to that effect, type after the #:

reboot

and press return. Your computer will restart now. Please let us know if this solved your issue, or if the steps above did not work, or could not be performed for some reason.

1. If possible, set the system clock as instructed here. If you can only start up in Recovery mode, see below.

Select Get Help Online. Safari will launch. While in Recovery, you'll have no access to your bookmarks, but you won't need them. Load this web page.

Triple-click anywhere in the line below to select it:

date 0801000014

Copy the selected text to the Clipboard by pressing the key combination command-C.

Quit Safari. You'll be returned to the OS X Utilities screen.

Select

Utilities ▹ Terminal

from the menu bar. A Terminal window will open. Paste into the window by pressing the key combination command-V.

Wait for a new line ending in a dollar sign ($) to appear below what you entered. If it doesn't appear, press return.

Quit Terminal to return to the main screen. Try the installation again.

2. If the date is correct, or if you still can't install after correcting it, see below.

Start up in Recovery mode, launch Disk Utility, select the startup volume ("Macintosh HD," unless you gave it a different name), and run Repair Disk (not Repair Permissions.) If any problems are found, repeat. Then restart as usual.

If you don't already have a current backup, you must back up your data before you take the above step. You may be able to back up, even if the system isn't fully functional. Ask if you need guidance.

Directory corruption in a MacOS journaled volume is always the result of a drive malfunction. It's not caused by power failures, system crashes, or anything else. You might choose to tolerate such a malfunction once in the life of a drive. If it's repeated, the drive must be replaced, or there is some other hardware fault that needs to be corrected. Ignoring repeated directory errors will result in data loss.

Hello again,

The cmd + s isn't going to work if it didn't work the first time.

Did you do Linc's steps?

Hello once more!

Holiday greetings to you as well! 😀

If your wife made Time Machine-back-ups then you've opened up ways to installing Yosemite that aren't perhaps 100% safe.

The short of it:

- First, we can make a Yosemite installer-USB on a thumbdrive you might have laying around. It needs to be a thumbdrive of at least 8GB

- We can boot from that thumbdrive, erase your entire disk and attempt to install then.

- Once install was successful, use setup assistant or migration assistant to recover your data and applactions from Time Machine.

The risks:

- Be aware that, if you still cannot install Yosemite after erasing the entire disk, you can only try to reinstall Snow Leopard from the original install-DVD. Keep it ready in case you need it.

- Following this guide will also destroy any extra partitions you might have created, including Boot Camp should you use it. You will need to re-setup Boot Camp, reinstall Windows. Time Machine does not back-up content in Windows!

- If that also fails, your HDD needs replacement. Don't start with this guide unless you have spare computers to work on and time to bring the computer to a repair shop.

- Also, maybe it's all just not worth the risk or the potential cost to you. You decide. Just don't stop making Time Machine back-ups because your drive or your partition-table might be failing.

Please first check at " > System Preferences > Time Machine" when the last successful back-up was completed. Also click the [options]-button to make sure no important directories are being EXcluded from Time Machine.

Lastly, you could browse the Time Machine back-ups itself on your external drive to see with your own eyes if things are backed-up there.

Here's where the guide starts in earnest, please read through it before you start:

1/ Go to your Applications-folder in the Finder and trash the file called "Install OS X Yosemite" Re-download it from the Mac App Store. Make sure your internet connection is absolutely stable. Preferably, disable security software including OS X firewall from "System Preferences > Security" and wifi from "System Preferences > Network" on your Mac and connect an ethernetcable straight from your computer to your modem/router without hubs, switches, etc in between. https://itunes.apple.com/app/os-x-yosemite/id915041082?mt=12

- test if this perhaps has already solved your problem. If so, enjoy Yosemite 🙂

2/ Plug in the thumbdrive, open Disk Utility from /Applications/Utilities/ and find your thumbdrive in the left column. Unplug all other drives from your Mac if you have any connected, including your Time Machine drive. Click on the not-indented mention of your thumbdrive - probably "XXGB DRIVENAME", find the [erase]-tab to the right. Use the formatting "mac os extended (journaled)" and pick the name Untitled (with capital U, this is important later)

3/ Once successfully formatted, open the Terminal, also from /Applications/Utilities/, and copy-paste the command below into the Terminal, after the $:

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Yosemite.app --nointeraction

Press return and when it asks for a password, please be aware that you will not see any dots or stars **** - you will have to enter your login/admin-password blindly and press return again.

If successful, you will see the Terminal working on turning the thumbdrive into a bootable installer.

4/ Afterwards, shut down your Mac, boot the computer with the [alt]-key pressed on your keyboard (sometimes [option]-key) and a startup manager will appear where you will see the Yosemite-installer to boot from. Do this.

After a few minutes, you will see a Utilities-screen. Choose Disk Utility, click on your computer's internal HDD - usually "XXXGB Hitachi" or "XXXGB WD" - and erase the entire drive to Mac Os Extended (journaled). Choose any name you like, as long as it doesn't contain special characters. To be clear: erase not just the indented Macintosh HD partition, but the whole XXXGB drive. Now you'll understand why having a good Time Machine back-up is important.

5/ Once the erase is completed (usually takes no longer than a few seconds), close Disk Utility and proceed to install Yosemite on your computer.

After installing, you'll be presented with a screen that asks you: "Do you already have a Mac?" At this screen, plug in your Time Machine and choose to recover your entire system from it.

Long guide, but did it work?

You can make a bootable USB stick to install using this free program.

Bootable USB Flash Drive – Diskmaker X

quentinmitchell wrote:

Hi Eric,

Thanks.

Have installed Diskmaker X but it can't find OS X Install. Spotlight comes up with nothing and the FAQ has nothing about it.

Sorry to trouble you but 'Help!'.

Regards,

Quentin Mitchell

Nobody read my guide, I haz a sad.

quentinmitchell wrote:

After failing to download the installer from App store I have followed CellarDwlr's note to the letter but on trying to install from the thumb drive I get

This is not a supported method of installing the operating system.

Please run install OS X 10.10.ap that you downloaded from the App store.

Quentin

Hello!

This is the first time I'm seeing that. Even Googling the phrase only gives me a few hits, like this one: Yosemite upgrade, now this "Device or computer could not be verified" (without solution)

If you really did step 4 of my guide to the letter (you can always try and do step 4 one more time now) then something is wrong with the harddrive.

Finally, you can also try and download the yosemite installer from another computer and network if you have access to that. Perhaps something continually goes wrong while downloading from the App Store, perhaps due to proxy filters or firewalls in the network.