Unplanned switch: Workload Site to Asynchronous Target Site Using SRDF/Star and SYMCLI

 

Topic

Managing SRDF

Selections

Select SRDF management tool: Managing SRDF using Solutions Enabler SYMCLI

Select SRDF using SYMCLI task: Managing Concurrent SRDF/Star

Select a Concurrent SRDF/Star task: Unplanned switch: Workload site to Asynchronous target site

 

 

Contents

Unplanned switch: Workload Site-> Asynchronous Target Site using SRDF/Star 4

About this procedure. 4

Task 1:  Disconnect both target sites. 5

Task 2:  Determine which site’s data will be kept during the switch. 6

Task 3:  Switch the workload to the asynchronous site. 6

Task 4:  Protect the synchronous site. 6

 


 

Unplanned switch: Workload Site-> Asynchronous Target Site using SRDF/Star

This procedure descibes the steps to switch the SDRF/Star protection from the primary workload site to the asynchronous target site in response to an unplanned event.

About this procedure

·    This procedure was created using Solutions Enabler version 7.3.

·    This procedure is based on content in the the following documents:

·     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 Notes

You can download these guides from EMC Online Support (registration required): https://support.EMC.com.

Note:  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:

Task 1:     Disconnect both target sites

                       

   1. [   ]    Log in to the control server for the asynchronous target site (SiteC).

   2. [   ]    Type the symstar –cg CompositeGroupNamedisconnect –trip –site Site command to change the Star state to “PathFail” for both the Synchronous and Asynchronous Target sites.

To disconnect SiteB and SiteC:

 

symstar -cg train125 disconnect -trip -site SiteC

symstar -cg train125 disconnect -trip -site SiteB

 

   3. [   ]    Type the symstar –cg CompositeGroupName query command to verify that the state is “PathFail” for both the 1st Target site and the 2nd Target.

To query compposite group train125:

symstar -cg train125 query

 

Output similar to the following is displayed:

 

Site Name                                     : SiteC

 

Workload 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_SiteB

Last Action Status                            : Successful

Last Action Timestamp                         : 05/25/2010_10:12:31

 

STAR 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

  }

. . .

 

   4. [   ]    Note the value of “Asynchronous Target Site Data most Current“ in the output.

Task 2:     Determine which site’s data will be kept during the switch

                       

The next step varies depending on the value of “Asynchronous Target Site Data most Current”.

·        If the value is “No”, data at the Synchronous Target site (SiteB) is the most recent.

 

Use the –keep_data argument to specify the Synchronous Target site (SiteB).

·        If the value is “Yes”, data at the Asynchronous Target site (SiteC) is the most recent.

 

Use the –keep_data argument to specify the Aynchronous Target site (SiteC).

Task 3:     Switch the workload to the asynchronous site

                       

   1. [   ]    Switch the workload to the asynchronous  target site (SiteC) 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 SiteC -keep SiteB

 

Output similar to the following is displayed:

 

A STAR Switch operation is

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

 

Switch_SiteC ................................................. Started

. . .

Switch_SiteC ................................................. Done

 

Task 4:     Protect the synchronous site

                       

   1. [   ]    Type the symstar –cg CompositeGroupName protect –site Site command to protect the asynchronous target site.

To protect SiteB:

 

symstar -cg train125 protect -site SiteB

 

   2. [   ]    Type the symstar –cg CompositeGroupName query command display the composite group.

To display composite group train125:

 

symstar -cg train125 query

 

Output similar to the following is displayed:

 

Site Name                                     : SiteC

 

Workload Site                                 : SiteC

1st Target Site                               : SiteA

2nd Target Site                               : SiteB

 

Composite 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_SiteB

Last Action Status                            : Successful

Last Action Timestamp                         : 05/25/2010_12:34:57

. . .