title: Installing OSX: file system verify or repair failed
body: <p>After I've pressed cmd + R at start up, I try to reinstall. It takes about 20 minutes before I get an error saying:</p>
  
  <pre><code>file system verify or repair failed
  quit the installer to restart your computer and try again
  </code></pre>
  
  <p>I've tried to First Aid through Disk Utility, but then i get this error:</p>
  
  <pre><code>First aid process has failed. if possible back up the data
  on this volume. Click done to continue.
  </code></pre>
  
  <p>And Disk Utility Erase gives this:</p>
  
  <pre><code>The disk disk1 couldn't be ejected
  Couldn't unmount disk.
  Operation failed..
  </code></pre>
  
  <p>Does anyone know the solution to this? My mac has been freezing and bugging out a lot lately, so I'm very much looking forward to a clean slate.</p>