Mac wont start after failed softwareupdate.

[Luke Griebling]

Yesterday I tried to update to the newest MacOS. First it failed bescause I had not enough space on my mac. Before second try I got the messegage that there was not enough space, so I deletet things and then I had like one more gb than I needed for the update. Should be working..... I started the update.... Mac restarted.... I think then there was the Apple Icon with the status bar, rest black....? Dont remember every step exactly. Later I came to the login Icon. I loged in. Then there was the Apple Icon with status bar, rest of the screen was the catalina image. The status bar went to like a third of the bar, then the hole screen went black. I tried waiting, nothing happend. Only way to get an image is to press the start button. It then turnes on and shows the same login screen as before. When I log in again, the same thing happens again over and over. (I tried this like ten times) Also tried some shortcuts. (turn off - turn on with holding shift, turning on and immediatly press command option r p, also with just pressing command r or option p. I am maybe describing it wrong - dont know.

Basically I was not able to startup the mac.

I pressed certain command to get the mac into recovery mode. Worked. The screen looked like as what it looks like when you set up a brand new Mac. Language, Apple ID, Password etc. Did all this. Then there was the option to recover from timemashine backup, to repair harddrive storage thing or to delete all things on it, there was also the option to reinstall macos, or to get help via safari. (those four options as shown below) I connected an external storage disk and reinstalled macos on it. Mac worked when this storage was connexted. (I did this because I didnt want to lose my data, or there was not enough space for that on the mac) With the new macos on the storage disk, mac seemed to be working. My data is not shown. Thats maybe because its running on an external disk or it has been deleted, I thought. Started that storage disk application. It showed that the internal storage was exactly as before I tried the update (~110gb of 128gb) -> think my data is still on that harddrive.

Right now I turned the mac off and disconnected the device because of time, I mean it was already like midnight and I had to sleep. The mac now shows the login sign when powering up without external disk - I also think when when powering up with. I think you will need to install macos again on the disk. Have no idea basically - That problem made me crazy.
Its again failing to login with no external disk with macos installed....

Can somebody show me what to do - I mean like step by step because I am really confused.
If there is a way I would also like to keep my data.

Sorry for that long text

Thanks for your help.
I'm soooo confused
Luke

 

[Fishrrman]

Unfortunately, this is what can happen when the internal drive gets "too full" -- the Mac won't boot, because there isn't enough free space available on the drive for temp files, RAM swap files, etc.

Do you have any kind of backup?

You need some way to:
a. Get the computer booted from an EXTERNAL drive,
and then
b. Access the internal drive and THROW STUFF AWAY until you create enough space so that the internal drive can boot again.

Here's what I'd suggest.
There may be other ways, but this one will work.

1. You'll need an external drive of some kind. It can be a hard drive, or SSD. It could even be a USB flash drive 32gb or larger. Smaller than that won't work.

2. Boot to INTERNET RECOVERY.
Command-OPTION-R at boot.
If you're on a laptop, you'll need a wifi password.
Internet recovery takes a while to load -- be patient.

3. You need to get to disk utility to erase the external drive. (NOT the internal one!)

4. You haven't told us WHICH VERSION OF THE OS you were using before you tried to upgrade.
If it was 10.12 Low Sierra or older, erase the drive to Mac OS extended with journaling enabled, GUID partition format.
If it was 10.13 High Sierra or 10.14 Mojave, erase it to APFS, GUID partition format.

5. Once the drive is erased, quit disk utility and open the OS installer. Begin "clicking through".

6. When the OS installer asks WHERE to install, "aim it" at the external drive, then let it go. The computer may reboot one or more times, and it will take a while. Be patient.

7. Once the OS is installed, you should see the setup screen. Create a new user account on the external drive, just enough to get you going. You DON'T need to "migrate anything". We just need a bootable drive.

8. When setup is done, you should be booted from the external drive, with an account setup, and "in the finder".

9. You may need to go to finder preferences and make hard drives visible in the finder.

10. Once this is done, now you should be able to access the internal drive, and start tossing stuff out. I'd remove about 15gb at least. Or, copy the stuff being removed to another drive.

11. Once you get free space established, you can power down, remove the external boot drive, and try booting from the internal drive again.

Hopefully, this will get you "a good boot", and you can decide what to do from there.

IMPORTANT:
If you get "permissions errors" when trying to remove things from the internal drive, do this:
a. Click ONE time on the internal drive's icon to select it
b. Type "command-i" (eye) to bring up "get info"
c. At the bottom of get info, click the lock and enter your password
d. Put a checkmark into the box "ignore ownership on this volume" (sharing and permissions)
d. Close get info.
You can now throw stuff away at will. But.. be careful!