Title

UnplannedSyncTargetWorkloadSwitchUsingSRDF/Star_sym001 Unplanned Synchronous Target Workload Switch Using SRDF/Star

Overview

This procedure provides the steps required to switch the SDRF/Star protection from the primary workload site (SiteA) to the synchronous target site (SiteB) in response to an unplanned event. This procedure is based on content from the following EMC technical documentation: EMC Solutions Enabler Symmetrix SRDF Family CLI White Paper: Implementing EMC SRDF/Star Composite Groups on Open Systems Applied Technology EMC Solutions Enabler Using SYMCLI to Implement SRDF/Star Technical NotesThese documents can be obtained from the EMC Powerlink website at:

http://Powerlink.EMC.comNote: For this procedure, the primary workload site is named SiteA, the synchronous target site is SiteB, and the asynchronous target site is SiteC, as shown in the following illustration:

1. Log in to the control server for the synchronous target site (SiteB) and change the Star state to PathFail for both the 1st Target site and the 2nd Target site by executing commands similar to the following:symstar -cg train125 disconnect -trip -site SiteC

symstar -cg train125 disconnect -trip -site SiteB

Once this is done, verify that the state is PathFail for both the 1st Target site and the 2nd Target site by executing a command similar to the following:

symstar -cg train125 queryWhen this command is executed, you should see output similar to the following:

Site Name : SiteBWorkload Site : SiteA

1st Target Site : SiteB

2nd Target Site : SiteC

Composite Group Name : train125

Composite Group Type : RDF2

Workload Data Image Consistent : Yes

System State:

{

1st_Target_Site : PathFail

2nd_Target_Site : PathFail

STAR : Tripped

Mode of Operation : Concurrent

}

Last Action Performed : Disconnect_SiteBLast Action Status : Successful

Last Action Timestamp : 05/25/2010_12:57:02STAR Information:

{

STAR Consistency Capable : Yes

STAR Consistency Mode : STAR

Synchronous Target Site : SiteB

Asynchronous Target Site : SiteC

Differential Resync Available : Yes

R2 Recoverable : Yes

Asynchronous Target Site Data most Current : No }

. . .Note the value associated with the Asynchronous Target Site Data most Current line of the output.(

2. Based on the value obtained for the Asynchronous Target Site Data in Step 1, determine which data will be kept during the switch. Typically, the data at SiteB is most recent and the query output indicates this with a value of No. In this case, the -keep_data argument for the switch command will indicate SiteB. In the event the line above displays Yes, the -keep_data argument would be SiteC.Switch the workload to the synchronous target site (SiteB) choosing which data will be kept, by executing a command similar to the following (from the appropriate switch site SiteB or SiteC):symstar -cg train125 switch -site SiteB -keep SiteB

When this command is executed, you should see a message similar to the following:

A STAR Switch operation is

in progress for composite group train125. Please wait...

Switch_SiteB ................................................. Started

. . . Switch_SiteB ................................................. Done

(

3. Protect the site with SRDF/A and verify that the site is protected by executing a set of commands similar to the following:

symstar -cg train125 connect -site SiteCsymstar -cg train125 protect -site SiteCsymstar -cg train125 query

When these commands are executed, you should see output similar to the following:

Site Name : SiteBWorkload Site : SiteB1st Target Site : SiteA

2nd Target Site : SiteCComposite Group Name : train125

Composite Group Type : RDF1

Workload Data Image Consistent : Yes

System State:

{

1st_Target_Site : Disconnected

2nd_Target_Site : Protected

STAR : Unprotected

Mode of Operation : Concurrent

}

Last Action Performed : Protect_SiteCLast Action Status : Successful

Last Action Timestamp : 05/25/2010_13:07:08 }

. . .

(

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UnplannedSyncTargetWorkloadSwitchUsingSRDF/Star_sym001