More RAM for buffers?

Josh Carroll josh.carroll at gmail.com
Thu Oct 2 18:09:57 UTC 2008


> inactive, cache, and buffer are all different types of "buffer".

That is my understanding as well.

> I'm fairly sure that inactive is memory used by program code.  When the
> program terminates, the memory is marked as inactive, which means the
> next time the program starts the code can simply be moved back to
> active and the program need not be reloaded from disk.

I think non-program code can also be "inactive".

For example, top memory output before:

Mem: 337M Active, 1455M Inact, 407M Wired, 352K Cache, 214M Buf, 1745M Free

and after:  find /usr/src -type f -print0 | xargs -0 cat > /dev/null 2>&1

Mem: 348M Active, 1905M Inact, 402M Wired, 912K Cache, 214M Buf, 1288M Free

I am also not sure exactly what constitutes each of these. I only know
what the top man page says. And for Buf it says:

       Buf:   number of pages used for BIO-level disk caching

I'm not entirely sure what "BIO-level disk caching" is, but it is
apparently NOT the caching of filesystem data.

Josh


More information about the freebsd-questions mailing list