I was selling my MBA which had 256G SSD, mid 2011 model. I wanted to securely erase the SSD and re-instal the software as I was selling the computer. However when I had done this and Mountian Lion was ready to go the storage only showed as 128G.
I looked in disk utility and it clearly showed only one 128G. However when I went to resster the data from Time Machine using the command -r funtion, I opened the disk utility which showed two hard drives of 120G, one called 'unitled' which was the one that had mounted and then a second called something like 'disk01' which had not mounted.
Try as I might I cannot get acess to this second disk of 120G so it looks like the total storage is 128G, yet I know that the storage used to be 256G.