View Full Version : Swap File filling up all available HD space

Jan 21, 2013, 11:36 AM
I have a retina MBP with 16GB RAM. The majority of my HD is allocated to Boot Camp, so I have only about 6GB free on my OSX partition. (I plan to change this in the near future.)

recently, I have been getting messages that my Startup Disk is almost full. This seems to happen regardless of what I have open, though it's usually standard stuff (Safari, Word, Preview, etc).

When I run GrandPerspective to see what's taking up so much space, it looks like the Swap File. When I restart, the space is freed up again.

is there a known reason for this? user error?

Jan 21, 2013, 11:46 AM
How much space are the swapfiles taking up? In general on my 8 GB iMac the swapfile space is 256 MB. It has grown to 2 GB every so often depending on what I'm doing.

What are you running that is using up RAM? And what size is your OS X partition.

Anonymous Freak
Jan 21, 2013, 12:21 PM
OS X Lion and Mountain Lion throw that error when your boot partition has less than 7 GB+15% total space available (So if you had a 50 GB partition, it would warn you at 7+(.15*50)=14.5 GB free; if you had only a 10 GB partition, it would warn you at 8.5 GB free.) Since you only have 6 GB available, you're over that threshold guaranteed.

Swap files are just a fact of life in UNIX-type systems. They swap inactive items out of memory onto disk, so that more physical memory is available when a new application launches. In general, you want to have as much free space on your boot partition as you have physical RAM. Obviously, you have less. I can't find any references to how much drive space (raw or percent,) OS X will leave free when swapping; but you are likely coming close to that point.