Cisco MDS SanOS Troubleshooting Guide -- Troubleshooting Cisco Fabric Services

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This section describes procedures used to troubleshoot Cisco Fabric Services (CFS) problems in the Cisco MDS 9000 Family multilayer directors and fabric switches.

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Contents

Overview

Many features in the Cisco MDS 9000 Family switches require configuration synchronization in all switches in the fabric. It is important to maintain configuration synchronization across a fabric for consistency.

As of Cisco MDS SAN-OS Release 2.0(1b), Cisco Fabric Services (CFS) provides a common infrastructure for automatic configuration synchronization in the fabric. It provides the transport function as well as a rich set of common services to the applications. CFS can discover CFS-capable switches in the fabric as well as their application capabilities.

Some of the applications that can be synchronized using CFS include:

  • IVR
  • NTP
  • DPVM
  • User roles
  • AAA server addresses, Radius and TACACS daemons
  • SFM
  • SDV
  • syslog
  • port-security
  • call home

As of Cisco MDS SAN-OS Release 3.2(1), the scope of configuration synchronization can be restricted to a limited set of switches within the physical scope of an application. CFS regions are designed to:

  • Fine tune the distribution of configuration for an application.
  • Restrict synchronization or merging of configuration information from a switch to a region, rather than distributing information across the entire physical scope of the application.
  • Span across some or all of the switches in the topology, within the physical scope of the application.

All switches in the fabric must be CFS capable. A Cisco MDS 9000 Family switch is CFS capable if it is running Cisco SAN-OS Release 2.0(1b) or later. Switches that are not CFS capable do not receive distributions and result in part of the fabric not receiving the intended distribution.

CFS has the following features:

  • Implicit CFS usage—The first time you issue a CFS task for a CFS-enabled application, the configuration modification process begins and the application locks the fabric.
  • Pending database—The pending database is a temporary buffer to hold uncommitted information. The uncommitted changes are not applied immediately to ensure that the database is synchronized with the database in the other switches in the fabric. When you commit the changes, the pending database overwrites the configuration database (also know as active database or the effective database).
  • CFS distribution enabled or disabled on a per-application basis—The default (enable or disable) for CFS distribution state differs between applications. If CFS distribution is disabled for an application, then that application does not distribute any configuration nor does it accept a distribution from other switches in the fabric.
  • Explicit CFS commit—Most applications require an explicit commit operation to copy the changes in the temporary buffer to the application database and distributes the new database to the fabric and releases the fabric lock. The changes in the temporary buffer are not applied if you do not perform the commit operation.
  • Globally disable CFS distribution—Use the no cfs enable command, in config mode, to isolate the switch from the rest of the fabric. The results acts like a single switch fabric. All other behaviors by the CFS and CFS enabled application are un-affected.
  • Enable IPV4 and IPV6 distribution from Fabric Manager—Go to Physical Attributes> Switches > CFS. GLOBAL indicates CFS distribution and IP MULTICAST indicates IPV4 and IPV6 distributions.

As of Cisco SAN-OS Release 3.1(2), some applications, such as Inter-VSAN Routing (IVR), require configuration distribution over some specific VSANs. These applications can specify to CFS the set of VSANs over which to restrict the distribution.

Initial Troubleshooting Checklist

Begin troubleshooting CFS issues by checking the following issues first:

Checklist

Checkoff

Verify that CFS is enabled for the same applications on all affected switches.

Verify that CFS distribution is enabled for the same applications on all affected switches.

If the CFS Regions feature is in use, verify that the application is in the same region on all the affected switches.

Verify that there are no pending changes for an application and that a CFS commit was issued for any configuration changes in a CFS enabled application.

Verify that there are no unexpected CFS locked sessions. Clear any unexpected locked sessions.

Verifying CFS Using Fabric Manager

Verifying CFS Using the CLI

Merge Failure Troubleshooting

Recovering from a Merge Failure with Fabric Manager

Recovering from a Merge Failure with the CLI

Lock Failure Troubleshooting

Resolving Lock Failure Issues Using Fabric Manager

Resolving Lock Failure Issues Using the CLI

System State Inconsistent and Locks Being Held

Clearing Locks Using Fabric Manager

Clearing Locks Using the CLI

Distribution Status Verification

Verifying Distribution Using Fabric Manager

Verifying Distribution Using the CLI

CFS Regions Troubleshooting

Distribution Failure

Regions for Conditional Service

Changing Regions

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