Owners Manual

Table 8. ME4 Series SAS controller module LEDs (continued)
LE
D
Description Definition
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). This is an
occasional condition that occurs while the system is booting.
● Blinking green—A CompactFlash flush or cache self-refresh is in progress, indicating
cache activity.
7 Network Port Activity
Status
4
● Off—The Ethernet link is not established, or the link is down.
● Green—The Ethernet link is up (applies to all negotiated link speeds).
8 Network Port Link Speed
4
● Off—Link is up at 10/100base-T negotiated speeds.
● Amber — Link is up and negotiated at 1000base-T.
9 Expansion Port Status Green—The port is connected and the link is up.
1
Cables must be qualified HD mini-SAS cable options.
2
Use a qualified SFF-8644 to SFF-8644 cable option when connecting the controller to a 12Gb SAS HBA.
3
Cache Status LED supports power on behavior and operational (cache status) behavior. See also Cache Status LED – power
on behavior on page 27.
4
When port is down, both LEDs are off. See also Power on/off behavior on page 27.
5
Once a Link Status LED is lit, it remains so, even if the controller is shut down using the PowerVault Manager or the CLI.
When a controller is shut down 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 power-cycled.
Cache status LED details
This section describes the behavior of the LEDs during powering on and off and cache status behavior.
Power on/off behavior
During power on, discrete sequencing for power on display states of internal components is reflected by blinking patterns
displayed by the Cache Status LED.
Table 9. Cache Status LED – power on behavior
Item Display states reported by Cache Status LED during power on sequence
Display state 0 1 2 3 4 5 6 7
Component VP SC SAS BE ASIC Host Boot Normal Reset
Blink pattern On 1/Off 7 On 2/Off 6 On 3/Off 5 On 4/Off 4 On 5/Off 3 On 6/Off 2 Solid/On Steady
Once the enclosure has completed the power on sequence, the Cache Status LED displays Solid/On (Normal), before assuming
the operating state for cache purposes.
Cache status behavior
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 supercapacitor 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
Storage system hardware
27