Operational Defect Database
BugZero found this defect 4856 days ago.
Data sources
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Hewlett Packard Enterprise | c02711640
CUSTOMER ADVISORY: HP StorageWorks B-series switches might experience a CP failover, faulted blade or faulted switch upon a back-end link error
Last update date:
2/28/2024
Affected products:
HPE B-series Encryption Option
HPE B-series Switch Expansion Upgrades
HPE Multi-protocol Router Blade Options
HPE 8/80 SAN Switch
HPE Converged Network Switches
HPE Encryption SAN Switch
HPE Storage SAN Director Switch
HPE StorageWorks 4/256 SAN Director Switch
HPE StorageWorks 4/64 SAN Switch
HPE StorageWorks 400 Multi-protocol Router
Affected releases:
No affected releases provided.
Fixed releases:
No fixed releases provided.
Description:
Info
Switches running with fabric operating system (FOS) v6.3.1b, v6.3.1c, v6.3.2, v6.4.0a, or v6.4.0b might experience a CP failover, a faulted blade or a faulted switch upon detection of a specific back-end link error. After detecting the back-end link error, the HP StorageWorks DC SAN Backbone Director Switch, DC04 SAN Director Switch or 4/256 SAN Director Switch platforms execute a CP failover. If the platform includes an HP StorageWorks SAN Director Multi-Protocol Router Blade Option, the blade will be faulted. After detecting the back-end link error, the HP StorageWorks 4/64 SAN switch, 8/80 SAN switch, 400 Multi-Protocol Router, 2408 FCoE Converged Network Switch or Encryption SAN Switch will be faulted. The FOS has always monitored back-end links for errors. These links internally connect ASICs or run along the backplane. One of the conditions that it monitors is BB_Credit . Historically, the FOS identified an issue when all available credit dropped to zero. FOS v6.3.1b and v6.4 introduced an enhanced detection mechanism that determines when a single credit is lost. The enhanced detection mechanism requires that a period of two seconds elapse with no traffic traversing the back-end or internal links before examining the credit values. If one or more credits are lost on a back-end or internal link after the two-second period, internal messages are sent to the blade drivers, and a RASlog message is generated. While losing a credit on a back-end link is rare, when this occurs, the following side effects might occur also. The HP StorageWorks 4/64 SAN switch, 8/80 SAN switch, 400 Multi-Protocol Router, 2408 FCoE Converged Network Switch or Encryption SAN Switch fault when they detect this condition. As a result, all ports are disabled. On the HP StorageWorks DC SAN Backbone Director Switch, DC04 SAN Director Switch or 4/256 SAN Director Switch, another message is generated every two seconds if the back-end or internal link continues to lack traffic. Under the right traffic conditions, these messages can overload the CPU and cause the CP to fail. No traffic disruption occurs. However, the standby CP takes over while the active-CP reboots. If an HP StorageWorks SAN Director Multi-Protocol Router Blade Option blade is connected to the back-end link where the error was detected, the blade will be faulted. The following table illustrates the actions and recovery for the various Fabric OS releases. FOS v6.3.1b, v6.3.1c, v6.3.2, v6.4.0a and v6.4.0b FOS v6.4.0c and v6.3.2a FOS v6.4.1 HP StorageWorks DC SAN Backbone Director Switch or DC04 SAN Director Switch CP Failover on single credit loss detection Internal log warning only when full credit loss is detected Internal log warning when single credit loss is detected HP StorageWorks 4/256 SAN Director switch CP Failover on single credit loss detection Internal log warning only when full credit loss is detected Internal log warning only when full credit loss is detected HP StorageWorks SAN Director Multi-Protocol Router Blade Option Blade will be faulted upon single credit loss detection Blade will be faulted only if full credit loss is detected Blade will be faulted only if full credit loss is detected HP StorageWorks DC SAN Director Switch 10/24 FCoE Blade Option Does not change behavior of chassis CP failover can happen when full credit loss is detected (6.4.0c only) Does not change behavior of chassis HP StorageWorks DC Backbone Switch Encryption Fibre Channel Blade Option Does not change behavior of chassis CP failover can happen when full credit loss is detected (6.4.0c only) Does not change behavior of chassis HP StorageWorks 4/64 SAN Switch Switch will be faulted upon single credit loss detection Switch faulted only when full credit loss is detected Switch faulted only when full credit loss is detected HP StorageWorks 400 Multi-Protocol Router Switch will be faulted upon single credit loss detection Switch faulted only when full credit loss is detected Switch faulted only when full credit loss is detected HP StorageWorks 8/80 SAN Switch Switch will be faulted upon single credit loss detection Switch faulted only when full credit loss is detected Switch will be faulted upon single credit loss detection HP StorageWorks 2408 FCoE Converged Network Switch Switch will be faulted upon single credit loss detection Internal log warning only when full credit loss is detected Internal log warning when single credit loss is detected HP StorageWorks Encryption SAN Switch Switch will be faulted upon single credit loss detection Internal log warning only when full credit loss is detected Internal log warning when single credit loss is detected
Scope
This issue affects all products in the Hardware or Software Platforms Affected section running with FOS 6.3.1b, 6.3.1c, 6.3.2, 6.4.0a, or 6.4.0b.
Resolution
HP recommends upgrading to Fabric OS v6.3.2a, v6.4.0c or v6.4.1 and above to avoid this issue. The code changes in this release does not prevent credit loss; rather, it prevents a failover and switch or blade fault if this rare credit loss event occurs. Workaround No known workaround exists that can eliminate the risk of experiencing this rare error condition. Proactive Updates Receive support alerts (such as Customer Advisories), driver updates, software, firmware, and customer replaceable components, in your e-mail through HP Subscriber's Choice. Sign up for Subscriber's Choice Driver, Patch, Security, and Support alerts at the following URL: http://www.hp.com/go/myadvisory
