HP StorageWorks 2000sa G2 Modular Smart Array User Guide (488320-005, March 2013)

HP 2000sa G2 Modular Smart Array User Guide 41
NOTE: Once a Link Status LED is lit, it remains so, even if the controller is shutdown via SMU or CLI.
When a controller is shutdown or otherwise rendered inactive —its Link Status LED remains
illuminated—falsely indicating that the controller can communicate with the host. Though a link exists
between the host and the chip on the controller, the controller is not communicating with the chip. To reset
the LED, the controller must be properly power-cycled (see Powering on/powering off on page 35).
10 Cache Status Green — Cache is dirty (contains unwritten data) and operation is
normal. The unwritten information can be log or debug data that
remains in the cache, so a Green cache status LED does not, by
itself, indicate that any user data is at risk or that any action is
necessary.
Off — In a working controller, cache is clean (contains no
unwritten data).
Blinking green — A CompactFlash flush or cache self-refresh is in
progress. Indicates cache activity (See also If the controller has
failed or does not start, is the Cache Status LED on/blinking? on
page 56).
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
CompactFlash memory. When cache flush is complete, the cache
transitions into self-refresh mode.
If the LED is blinking momentarily slowly, the cache is in a
self-refresh mode. 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 time-out 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
CompactFlash, which can take about 90 seconds.
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 CompactFlash.
11 Host Activity Off — Host ports have no activity.
Blinking green — At least one host port has I/O activity.
12 Expansion Port Status Off — The port is empty or the link is down.
On — The port is connected and the link is up.
LED Description Definition