Edit: I'm thinking about marking this question as answered since I've realized that I was pretty confused by the fact that file sizes were zero. This caused me to have a brain fart and panic. After reading the answers below I realized that I've often read these files before but it never occurred to me to check their filesizes. Therefore my question is misleading. I should have only asked why the file sizes were 0 only.
This is not a question about missing ram - but it may be a question about file sizes of 0. Am I looking at files that have zero file size because they are aliases to data in ram rather than on disk?
I understand that procinfo gathers information from the /proc directory on a linux box. But I've taken a look in that directory and can't figure out what files it actually queries. It appears as though most files are 0 bytes. What's really odd is that a particular file, kcore is listed as 128T on my system.
I've read that kcore represents the amount of ram on my system but I am sure I don't have 128T of ram (I have 12GB). I took a look at a second server that I rebooted and the file was 884M (that server has 1GB of ram).
I believe that, whether or not kcore is being used, procinfo is providing statistics based on data in ram. And I believe that is verified by procinfo's inability to keep data after a reboot.
I have two questions:
Would someone care to clarify these assumptions and add some helpful observations about this performance tool?
What is kcore if it's not a representation of the ram on my system (as I've read)?