Troubleshooting procedures help you diagnose problems.
Best practices for troubleshooting
Taking advantage of certain configuration options, and ensuring vital system access information has been recorded, makes the process of troubleshooting easier.
Understanding the medium errors and bad blocks
A storage system returns a medium error response to a host when it is unable to successfully read a block. The system response to a host read follows this behavior.
RAID write response time
This feature means that the RAID software layer, where redundancy exists to do so, can prevent drive bad behavior from having an unlimited impact on I/O performance. In addition, the system tries to avoid immediately committing to an array rebuild due to a brief offline event from a single drive, while there is full redundancy.
User interfaces for servicing your system
Thesystem provides a number of user interfaces to troubleshoot, recover, or maintain your system. The interfaces provide various sets of facilities to help resolve situations that you might encounter.
Event reporting
Events that are detected are saved in an event log. As soon as an entry is made in this event log, the condition is analyzed. If any service activity is required, a notification is sent, if you set up notifications.
Resolving a problem
Described here are some procedures to help resolve fault conditions that might exist on your system. A basic understanding of the system concepts is required.
Fibre Channel link failures You might need to solve problems on the system and its connection to the storage area network (SAN) when an optional Fibre Channel host interface adapter is being used.When a failure occurs on a single Fibre Channel link, the small form-factor pluggable (SFP) transceiver might need to be replaced.
Ethernet iSCSI host-link problems
If you are having problems attaching to the Ethernet hosts, your problem might be related to the network, thesystem, or the host.
Ethernet link failures
To assist in solving problems with the Ethernet ports that connect thesystem to one or more Ethernet networks, use this procedure.
Recover system procedure The recover system procedure recovers the entire storage system if the system state is lost from all control enclosure node canisters.The procedure re-creates the storage system by using saved configuration data.The saved configuration data is in the active quorum disk and the latest XML configuration backup file. The recovery might not be able to restore all volume data. This procedure is also known as Tier 3 (T3) recovery.
Servicing storage systems
Storage systems that are supported for attachment to the system are designed with redundant components and access paths to enable concurrent maintenance. Hosts have continuous access to their data during component failure and replacement.
Replacing parts You can remove and replace customer-replaceable units (CRUs) in control enclosures or expansion enclosures.