If PATH_SCOPE=CU is specified and path recovery determines that
a channel path needs to be removed from a device, the path is removed
from all devices defined to the control unit. Additionally, for intermittent
channel path errors, the system collects error statistics over a period
of time, and if the number of errors reaches or exceeds a threshold
value, the channel path is removed from all devices defined to the
control unit. The time period and threshold are controlled by the
PATH_INTERVAL and PATH_THRESHOLD parameters as follows:
- PATH_INTERVAL specifies the length of time to monitor for errors
(for example, 10 minutes).
- PATH_THRESHOLD specifies the minimum number of path-related errors
that must occur every minute for the specified period of time (PATH_INTERVAL)
before the path from the failing hardware component is removed from
all the affected devices.
For example, specifying a PATH_INTERVAL of 10 (minutes) and a
PATH_THRESHOLD of 20 (errors per minute) means that at least 20 errors
must occur every minute for 10 consecutive minutes before the path
from the failing hardware component is removed from all the affected
devices.
Note: - Do not set the interval and threshold values to a very low value
(for example: 1) because this may interfere with normal system recovery
and cause the system to remove channel paths unnecessarily.
- Changing the value of the interval and the threshold keywords
will not take effect until the next error is encountered and will
not affect actions previously taken.