disappearing storage

OmniDisksweeper can help you find what's hogging your disk space.

There is excessive swapping of data between physical memory and virtual memory.

That can happen for two reasons:

• You have a long-running process with a memory leak (i.e., a bug), or
• You don't have enough memory installed for your usage pattern.

Tracking down a memory leak can be difficult, and it may come down to a process of elimination.

In the Activity Monitor application, select All Processes from the menu in the toolbar, if not already selected. Click the heading of the Real Mem column in the process table twice to sort the table with the highest value at the top. If you don't see that column, select

View ▹ Columns ▹ Real Memory

from the menu bar.

If one process (excluding "kernel_task") is using much more memory than all the others, that could be an indication of a leak. A better indication would be a process that continually grabs more and more real memory over time without ever releasing it. Here is an example of how it's done.

The process named "Safari Web Content" renders web pages for Safari and other applications. It uses a lot of memory and may leak if certain Safari extensions or third-party web plugins are installed. Consider it a prime suspect.

If you don't have an obvious memory leak, your options are to install more memory (if possible) or to run fewer programs simultaneously.

The next suggestion is only for users familiar with the shell. For a more precise, but potentially misleading, test, run the following command:

sudo leaks -nocontext -nostacks process | grep total

where process is the name of a process you suspect of leaking memory. Almost every process will leak some memory; the question is how much, and especially how much the leak increases with time. I can’t be more specific. See the leaks(1) man page and the Apple developer documentation for details.

Select the System Memory tab. What values are shown in the bottom part of the window for Page outs and Swap used?

4.2 what?

ODS can't see the whole filesystem when you run it just by double-clicking; it only sees files that you have permission to read. To see everything, you have to run it as root.

Back up all data now.

Install ODS in the Applications folder as usual. Quit it if it's running.

Triple-click the line of text below to select it, then copy the selected text to the Clipboard (command-C):

sudo /Applications/OmniDiskSweeper.app/Contents/MacOS/OmniDiskSweeper

Launch the Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.

Paste into the Terminal window (command-V). You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up. If you see a message that your username "is not in the sudoers file," then you're not logged in as an administrator.

The application window will open, eventually showing all files in all folders. It may take some minutes for ODS to list all the files.

I don't recommend that you make a habit of doing this. Don't delete anything while running ODS as root. If something needs to be deleted, make sure you know what it is and how it got there, and then delete it by other, safer, means. When in doubt, leave it alone or ask for guidance.

When you're done with ODS, quit it and also quit Terminal.

About Time Machine's 'local snapshots' on Mac notebooks

Glad to hear you found the problem! 🙂