MBA Won't Restart After Failed Update

[Fizzoid]

Ok so I recently updated my (2012 I think) MBA to Catalina (yes yes, that was my first mistake). However, apart from a few apps no longer working it was actually ok

It ran an OS update and during the install, failed with a message saying I didn't have enough disk space, quit the updater, clear up some space and try again

So, I quit the updater, but now the Mac won't restart. It gets to around 50% on the progress bar and powers off. I've tried the NVRAM reset, but nothing. I've also run First Aid from the recovery console, but it's made no difference

Am I looking at a fresh install and restore from backup? Hopefully not, didn't back up for a while, but I think it may be my only option?

 

[flaubert]

If you can get into Recovery Mode (and it sounds like you have been able to), then you can do a Recovery Mode install over the top of your failed update to get back to a booting system. Just pay attention to prompts so that you don’t inadvertently erase your disk - you just want to install on top of your existing system. If it were me I’d try and boot from a backup, even an old backup, to do a clone onto a third disk as a little bit of insurance before starting anything tricky or unfamiliar.