For information about specific events, see the Event Descriptions Reference Guide, located on the Hewlett Packard
Enterprise Information Library website:
.
The event logs record all system events. It is very important to review the logs, not only to identify the fault, but also to
search for events that might have caused the fault to occur. For example, a host could lose connectivity to a disk group if
a user changes channel settings without taking the storage resources assigned to it into consideration. In addition, the
type of fault can help you isolate the problem to either hardware or software.
Isolate the fault
Occasionally it might become necessary to isolate a fault. This is particularly true with data paths, due to the number of
components comprising the data path. For example, if a host-side data error occurs, it could be caused by any of the
components in the data path: controller module, cable, connectors, switch, or data host (HBA/NIC).
If an expansion enclosure does not initialize
It may take up to two minutes for the enclosures in the storage system to initialize. If an expansion enclosure within the
storage system does not initialize:
l
Make sure the power cord is properly connected, and check the power source that it is connected to.
l
Verify that the expansion cabling connections for the enclosure are correct.
l
Perform a rescan to force a rediscovery of disks and enclosures in the storage system.
l
Power cycle the system.
l
Check the event log for errors.
Correcting enclosure IDs
When installing a system with disk enclosures attached, the enclosure IDs might not match the physical cabling order.
This is because the controller might have been previously attached to some of the same enclosures during factory
testing, and attempts to preserve the previous enclosure IDs if possible. To correct this condition, make sure that both
controllers are up, and perform a rescan using the SMU or the CLI. This will reorder the enclosures, but can take up to
two minutes for the enclosure IDs to be corrected. The rescan temporarily pauses all I/O processes, then resumes normal
operation.
To perform a rescan using the CLI, type the following command:
rescan
To rescan using the SMU:
1. Verify that both controllers are operating normally.
2. Select Maintenance > Hardware >
enclosure-ID
> Actions > Rescan All Disks.
3. Click Rescan.
Stopping I/O
When troubleshooting disk drive and connectivity faults, stop I/O to all volumes in the pool with the affected disk group,
from all hosts and remote systems as a data protection precaution. As an additional data protection precaution, it is
recommended to conduct regularly scheduled backups of your data.
IMPORTANT Stopping I/O to a disk group is a host-side task, and falls outside the scope of this document.
When on-site, you can verify there is no I/O activity by briefly monitoring the system LEDs. When accessing the storage
system remotely, this is not possible. Remotely, you can use the
show disk-group-statistics
CLI command to
determine if input and output has stopped. Perform these steps:
1. Using the CLI, run the
show disk-group-statistics
command.
50
Chapter 7
Troubleshooting