Mountain Lion and memory problems
I have a Macbook Air (1.8 GHz i7, 4 GB RAM, 250 GB SSD) and just installed Mountain Lion. Previous OS was Lion, final version. And suddenly my computer is bogging down and I get messages that say "Your Mac OS X startup disk has no more space available for application memory." I get these messages and my computer hangs--this has happened several times today and I've had to force restart.
It is not because I have too little hard disk space available, because 165 GB of my 250 GB hard drive is free. And it is not because I am running too many apps--I even got this message once with the only open app being Activity Monitor.
Here's what I've tried:
1. Disabling Java and Javascript
2. Repairing disk permissions
3. Verifying the disk (using Disk Utility)
4. Restarting
5. Running Omni Disk Sweeper (which confirms that most of my hard disk is free)
I have not turned off Spotlight or Backblaze.
The processes that keep spiking between 400 MB and 1 GB of memory (per Activity Monitor) are kernel_task, mds, and bztransmit (the last might be from Backblaze, but I've even had these messages when this process was using almost no memory).
Right now I've been able to use Safari long enough to file this question to Apple Support Communities, but I have only 8.7 MB of free RAM (per Activity Monitor), which makes no sense given the 4 GB RAM in my Mac and the fact that I'm running only Activity Monitor and only one window in Safari.
Suggestions appreciated!
MacBook Air, OS X Mountain Lion