R/Evolution 2000 Series, Troubleshooting Manual

Page: 32 / 130

32 R/Evolution 2000 Series Troubleshooting Guide • May 2008
Using Controller Module Status LEDs
During normal operation, the FRU OK LED is green, the cache status LED can
be green or off, and the other controller module status LEDs are off.
If the FRU OK LED is off , either:
■
The controller module is not powered on. If it should be powered on, check that
it is fully inserted and latched in place, and that the enclosure is powered on.
■
The controller module has failed. Check the event log for specific information
regarding the failure.
If the Fault/Service Required LED is steady yellow , a fault occurred or service
action is required.
If the Cache status LED is blinking green , a cache flush or self-refresh is in
progress. No action is needed.
■
If the LED is blinking evenly, a cache flush is in progress. When a controller
module loses power and write cache is dirty (contains data that has not been
written to disk), the super-capacitor pack provides backup power to flush (copy)
data from write cache to Compact Flash memory. When cache flush is complete,
the cache transitions into self-refresh mode.
■
If the LED is blinking slowly, a cache flush is in progress. In self-refresh mode,
if primary power is restored before the backup power is depleted (3–30 minutes
depending on various factors), the system boots, finds data preserved in cache,
and writes it to disk. This means the system can be operational within 30
seconds, and before the typical host I/O timeout of 60 seconds at which point
system failure would cause host-application failure. If primary power is restored
after the backup power is depleted, the system boots and restores data to cache
from Compact Flash, which can take about 90 seconds.
Note – The cache flush and self-refresh mechanism is an important data protection
feature; essentially four copies of user data are preserved: one in each controller's
cache and one in each controller's Compact Flash.
If the Fault/Service Required LED is blinking yellow , one of the following
errors occurred:
■
Hardware-controlled power-up error
■
Cache flush error
■
Cache self-refresh error
If the OK to Remove LED is blue , the controller module is prepared for
removal.