Real and availible RAM

agent dero dero at
Mon May 5 06:29:14 PDT 2003

I have been looking through the kernel boot messages in /var/log while
working on some custom kernel compile work, and I came across something
that I think is very interesting, but doesn't make sense.
real memory  = 100663296 (98304K bytes)
avail memory = 94580736 (92364K bytes)

This tells me that FreeBSD recognizes my 98MB of RAM, but it only uses 92MB?
Are the 6MB of RAM that are left getting shafted, and just using power,
but not being addressed by FreeBSD? Does this slow down my machine at all,
I mean, is there a percentage to this? Where only x% of 100% RAM is
availible or usable?

Also, I use phpSysInfo to judge the status of most of my remote servers,
and it shows the caches and buffers as part of the whole chunk of used
RAM, so at one point it can be up to 95% of the RAM. But then 10 minutes
later it will have dropped back down to 50% or so, showing that the
buffers were somehow cleared? Is there anyway to do this manually?

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