Hi. Since when I installed OS X Yosemite on my rMBP (without touching any partition on the SSD) I've had a problem about disk space. Macintosh HD seems to be full (Finder says "0 bytes free" and some apps encounter errors because they can't write on the boot volume), which is very strange because I don't remember to have filled up my SSD. So I downloaded OmniDiskSweeper to verify which files were taking up so much disk space. The result? According to OmniDiskSweeper, all the files on Macintosh HD only fill 93.2 GB of 250 GB of space. So why are more than 150 GB unavailable? I opened Disk Utility and I enabled the option "Show every partition" in the Debug menu. Then I understood that, probably, there is something wrong with partitions: http://s30.postimg.org/vr795rtz4/image.jpg http://s30.postimg.org/wqxk1h94w/image.jpg http://s30.postimg.org/frolm7xxc/image.jpg What should I do?