46 Troubleshooting
If the controller has failed or does not start, is the Cache Status LED on/blinking?
NOTE: See also “Cache Status LED details” (page 66).
Transporting cache
To preserve the existing data stored in the CompactFlash, you must transport the CompactFlash from the failed 
controller to a replacement controller using the procedure outlined in HPE MSA Controller Module Replacement 
Instructions shipped with the replacement controller module. Failure to use this procedure will result in the loss of data 
stored in the cache module.
CAUTION: Remove the controller module only after the copy process is complete, which is indicated by the Cache 
Status LED being off, or blinking at 1:10 rate.
Isolating a host-side connection fault 
During normal operation, when a controller module host port is connected to a data host, the port’s host link status/link 
activity LED is green. If there is I/O activity, the LED blinks green. If data hosts are having trouble accessing the storage 
system, and you cannot locate a specific fault or cannot access the event logs, use the following procedure. This 
procedure requires scheduled downtime.
IMPORTANT: Do not perform more than one step at a time. Changing more than one variable at a time can complicate 
the troubleshooting process.
Host-side connection troubleshooting featuring host ports with SFPs
The procedure below applies to MSA 1050 controller enclosures employing small form factor pluggable (SFP) transceiver 
connectors in 8 Gb FC, 10GbE iSCSI, or 1 Gb iSCSI host interface ports. In the following procedure, “SFP and host cable” is 
used to refer to FC or iSCSI controller ports used for I/O or replication.
NOTE: When experiencing difficulty diagnosing performance problems, consider swapping out one SFP at a time to see 
if performance improves.
Table 17 Diagnostics LED status: Rear panel “Cache Status”
Answer Actions
No, the Cache LED status is off, and the controller 
does not boot.
If valid data is thought to be in Flash, see Transporting cache; otherwise, 
replace the controller module.
No, the Cache Status LED is off, and the controller 
boots.
The system has flushed data to disks. If the problem persists, replace the 
controller module.
Yes, at a strobe 1:10 rate - 1 Hz, and the controller does 
not boot.
See Transporting cache.
Yes, at a strobe 1:10 rate - 1 Hz, and the controller 
boots.
The system is flushing data to CompactFlash. If the problem persists, 
replace the controller module.
Yes, at a blink 1:1 rate - 1 Hz, and the controller does 
not boot.
See Transporting cache.
Yes, at a blink 1:1 rate - 1 Hz, and the controller boots. The system is in self-refresh mode. If the problem persists, replace the 
controller module.