kernel process helps protect the integrity of disk volumes
by flushing volatile cached file system data to disk.
The kernel places all
in a number of queues.
process works through the queues
in a round-robin fashion,
usually processing one queue per second.
on that queue,
process forces a write out to disk of its dirty buffers.
The usual delay between the time buffers are dirtied
and the time they are synced
is controlled by the following
| Variable|| Default|| Description|
| kern.filedelay|| 30|| time to delay syncing files|
| kern.dirdelay|| 29|| time to delay syncing directories|
| kern.metadelay|| 28|| time to delay syncing metadata|