Go to the menu bar and select Terminal.Ĭopy the files you want to rescue using cp.

Method A – If you want to save individual files: The advantage is that there is no stress on the faulty disk. This loads the recovery mode from the internet, which will be very slow.

Press cmd+ alt+ R before the boot screen appears to enter internet recovery mode.

Get an external backup disk that has enough capacity and connect it.

This answer assumes you don't have FileVault enabled. The risk that the disk breaks entirely any moment now is very high. Whatever you do, leave the faulty disk alone until you know what you are going to do.

So please, try to answer in terms I will understand.

I'm not very computer savvy, but I can manage my way through Terminal with a lot of instruction. Since Disk Utility tells me everything is okay, am I able to somehow mount an external, and backup files? Possibly through Terminal? And If I were to use the drive with the old Time Machine backup on it, would I have to delete the backup before writing new data to the drive? Most of the data in the backup is the same, but there are a few GBs of new files I'd like to backup as well.

I have an outdated Time Machine backup, made before I upgraded from Mountain Lion to El Capitan. Back up as much of the data as possible and replace the disk. This disk has a hardware problem that can't be repaired. I am able to boot into Recovery Mode, and I can even run Disk Utility (it doesn't detect any problems.) However, when I attempt to reinstall the OS, it tells me: The progress bar would take forever to reach 100%, and then it would just stop there once it reached it all the while the fan running loudly. Out of the blue, my iMac (late 2010, running El Capitan) started refusing to boot.

Backup my mac to external hard drive