My hard disk is starting to get a bit cramped, with only 30GB available. I'm about download Lion and I'd like to know if I'll need to free up some space before I install it.

Also, I've read that Lion creates a hidden partition with a bare-bones copy of OS X for emergency system recovery. How large is it? How much space will I lose after installing Lion?

2 Answers 2


According to http://www.apple.com/support/lion/installrecovery/ you only need 7G of free space.

Amazingly small amount of space considering the download is 3.6G itself.

Many are reporting gaining back between 5 and 10 GB of space as Lion is more compact than Snow Leopard.


You should be fine with 30GB of space. Lion will take about 4 GB on your hard drive (plus the installer - which is automatically deleted afterwards) and it makes a 650MB recovery partition, which you can remove manually, if you so desire.

  • 1
    Will Lion take an extra 4 GB beyond a Snow Leopard install? Or will it remove ??? GB of Snow Leopard stuff and replace it with 4 GB?
    – hotpaw2
    Commented Jul 20, 2011 at 19:17
  • @Hotpaw2 - I'm guessing that it removes the old files, since the OS is, by itself complete. (You can use the same installer on a DVD or USB drive to do a fresh install.)
    – Moshe
    Commented Jul 20, 2011 at 19:59
  • Just to note, I saw a post somewhere online about this, but I can't seem to find it...
    – Moshe
    Commented Jul 20, 2011 at 20:07

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .