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HP 2000SA G2-Modular-Smart-Array User Manual

Page 41

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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