mbuf statistics

[Hooman Fazaeli]

Hi,

On an idle freebsd 9.3 system:

> vmstat -z | egrep "mbuf_cluster|ITEM" | column -t
ITEM           SIZE   LIMIT   USED   FREE  REQ    FAIL  SLEEP
mbuf_cluster:  2048,  10284,  1152,  56,   4237,  0,    0

> netstat -mb | grep "mbuf clusters in use"
512/696/1208/10284 mbuf clusters in use (current/cache/total/max)

one can see that:

current + cache == total == USED + FREE

but the current/cache values as reported by netstat
are very different form USED/FREE values reported by vmstat, so
they should have different meaning.

The question is: what is the exact meaning of USED/FREE and
current/cache values? Is there any relationship between them?

-- 
Best regards
Hooman Fazaeli