

The figure in the Shared column is the one to believe for memory usage.

In reality, they each only occupy as much memory as they need. The sizes shown here are the maximum sizes of these file systems. The first thing that hits you when you look at those values is that they are many times larger than the figure in the Shared column. -type=tmpfs: Only report on the tmpfs file systems.-total: Display a line with totals at the bottom of the output.-h (human): Use sensible, best-fit units.To see which tmpfs file systems are present, use the df command. These are file systems that are created in memory to facilitate the efficient functioning of the operating system. The figure in the Shared column represents memory devoted to holding tmpfs RAM-based file systems. That is, the RAM is being used by applications and other user space processes and by the kernel in its efforts to make the performance of your computer as good as can be. That’s not necessarily a bad thing, and almost certainly means you’ve got a perfectly normally functioning system that is regulating the use of RAM correctly. Because the Used column contains the Buffers and Cache figures, it’s not uncommon for perfectly functioning Linux systems to have very little RAM listed as “free.” This column holds the figure for the amount of RAM that is not being used by anything. So this column really means “all RAM that is in use by something, even if it can be reclaimed instantly.” The Free Column Freeing up this RAM and using it for other applications won’t impact the correct operation of your Linux system-nothing’s going to break-but it might impact the performance of the system. If a request for memory is received that can only be serviced by relinquishing some of the RAM the kernel is using for its own devices, then that is what happens, seamlessly. At least they would be fighting if the kernel wasn’t refereeing. This is the precious resource that all of the running processes are fighting over. It’s how much RAM you have installed on your motherboard. Let’s see what the figures in the columns represent. Instead of a Buff/cache column, we get a Buffers column and a Cache column. Here are the figures in a table: total used free shared buffers cache available To separate the Buff/cache figures into their own columns, use the -w (wide) option: free -w Free: The remaining (unused) swap space.

#LINUX SEE FREE MEMORY SOFTWARE#

We’ll introduce the columns here, then look at them in more detail shortly. The columns for the memory line are as follows: The top line reports on system memory, the bottom line reports on swap space.
