gone device timers and zombie state entries. There are tunables
that can be used to select a number of parameters.
loop_down_limit - how long to wait for loop to come back up before
declaring
all devices dead (default 300 seconds)
gone_device_time- how long to wait for a device that has appeared
to leave the loop or fabric to reappear (default 30 seconds)
Internal tunables include (which should be externalized):
quick_boot_time- how long to wait when booting for loop to come up
change_is_bad- whether or not to accept devices with the same
WWNN/WWPN that reappear at a different PortID as being the 'same'
device.
Keen students of some of the subtle issues here will ask how
one can keep devices from being re-accepted at all (the answer
is to set a gone_device_time to zero- that effectively would
be the same thing).