Recovering From an SRDF Data Replication Error

When an error occurs at the data replication level, the error is reflected in the status of the resource in the replication resource group of the relevant device group. This changed status appears in the Data Replication status field in the output of the geoadm status command for that protection group.

This section contains information about the following topics:

• How to Detect Data Replication Errors

• How to Recover From an SRDF Data Replication Error

How to Detect Data Replication Errors

1. Check the status of the replication resources by using the clresource status command.

   # clresource status -v sc_geo_dr-SRDF-protectiongroupname-srdfdgname

   For information about how different Resource status values map to actual replication pair states, see Table 2-4.

   Running the clresource status command might return the following:

   …
   -- Resources --
   
               Resource Name       Node Name           State     Status Message
               -------------       ---------           -----     --------------
     Resource: sc_geo_dr-SRDF-srdfpg-devgroup1 pemc1  Online    Online - Partitioned
     Resource: sc_geo_dr-SRDF-srdfpg-devgroup1 pemc2  Offline   Offline
   …

2. Display the aggregate resource status for all device groups in the protection group by using the geoadm status command.

   For example, the output of the clresource status command in the preceding example indicates that the SRDF device group, devgroup1, is in the Suspended state on cluster-paris. Table 2-4 indicates that the Suspended state corresponds to a resource status of FAULTED. So, the data replication state of the protection group is also FAULTED. This state is reflected in the output of the geoadm status command, which displays the state of the protection group as Error.

   phys-paris-1# geoadm status
   Cluster: cluster-paris
   
   Partnership "paris-newyork-ps"  : OK
      Partner clusters             : cluster-newyork
      Synchronization              : OK      
      ICRM Connection              : OK
   
      Heartbeat "paris-to-newyork" monitoring "cluster-newyork": OK 
         Heartbeat plug-in "ping_plugin"             : Inactive
         Heartbeat plug-in "tcp_udp_plugin"          : OK
   
   Protection group "srdfpg"   : Error
         Partnership         : paris-newyork-ps
         Synchronization     : OK
   
         Cluster cluster-paris    : Error
            Role                  : Primary
            PG activation state   : Activated
            Configuration         : OK
            Data replication      : Error
            Resource groups       : OK 
      
         Cluster cluster-newyork  : Error
            Role                  : Secondary
            PG activation state   : Activated
            Configuration         : OK
            Data replication      : Error
            Resource groups       : OK
    

How to Recover From an SRDF Data Replication Error

To recover from an error state, you might perform some or all of the steps in the following procedure.

1. Use the procedures in the SRDF documentation to determine the causes of the FAULTED state.
2. Recover from the faulted state by using the SRDF procedures.

   If the recovery procedures change the state of the device group, this state is automatically detected by the resource and is reported as a new protection group state.

3. Revalidate the protection group configuration.

   phys-paris-1# geopg validate protectiongroupname 

   protectiongroupname

   Specifies the name of the SRDF protection group.

   If the geopg validate command determines if the configuration is valid, the state of the protection group changes to reflect that fact. If the configuration is not valid, geopg validate returns a failure message.

4. Review the status of the protection group configuration.

   phys-paris-1# geopg list protectiongroupname

   protectiongroupname

   Specifies the name of the SRDF protection group.

5. Review the runtime status of the protection group.

   phys-paris-1# geoadm status