My MacBook Air keeps saying the start up disc is full...but I haven't used all the memory...help

Question

I keep getting a message to say my start disc is full and I cant understand why. I dont have a lot of things saved on it and it affecting the operating of my laptop ie, freezing/wont download new mail.
Anyone had this issue before? Any ideas whats going on?
Thanks

Answer 1

First, that's not Local Snapshots -- if there was only 200 MB free, any Local Snapshots had been deleted long before (they're automatically deleted to keep your drive below 80%).
If it starts shrinking rapidly again, see Where did my Disk Space go?
There are lots of possibilities, but your symptoms sound a bit like one (or both) of these:
• Something going wrong sending thousands of messages to your logs (per the yellow box in the above link).  You'll need to fix whatever that is as well as delete the old log files.
• An app (or apps) with a memory leak, making OSX use ridiculous amounts of virtual memory (not listed in the link).  While the space is shrinking, select Go > Go to Folder from a Finder menubar, then type /var/vm in the prompt.  That will produce a list of your swap files.  Those are created as needed; the first two are 67 MB, then each additional file is double the size of the previous one, so they can get pretty large.  They're deleted and started over after a Restart.
(There's probably also a sleepimage file there the same size as your installed RAM.  That's normal.)