Planned Switch From Synchronous Target to Primary Workload 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: Planned switch: Synchronous target site to primary workload site

 

 

Contents

Planned switch: Synchronous Target Site -> Primary Workload Site using SRDF/Star 4

About this procedure. 4

Task 1:  Halt host applications to ensure data is consistent at all sites. 5

Task 2:  Halt the composite group. 5

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

Task 4:  Protect the workload site using SRDF/Star 6

 


 

Planned switch: Synchronous Target Site -> Primary Workload Site using SRDF/Star

This procedure describes the steps to:

·        Gracefully shutdown the SDRF/Star protection at the synchronous target site (SiteB) and

·        Return to the primary workload site (SiteA) and,

·        Resume protection.

 

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:     Halt host applications to ensure data is consistent at all sites

                       

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

   2. [   ]    Type the symstar –cg CompositeGroupName query command to display the protection status of the composite group.

To query compposite 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                             : Connected

  2nd_Target_Site                             : Protected

  STAR                                        : Unprotected

  Mode of Operation                           : Concurrent

 

   3. [   ]    Verify that the System State for both Target Sites (SiteA and SiteB) is either “Connected” or “Protected”.

IMPORTANT:   This procedure requires both sites to be at a minimum state of “Connected

The next step varies depending on the System State for both Target Sites (SiteA and SiteB).

·        If the System State for both Target Sites is Connected or Protected, skip toStep 5. [   ].

·        If the System State for both Target Sites is NOT Connected or Protected, proceed to Step 4. [   ].

 

   4. [   ]    Type the symstar –cg CompositeGroupName connect –site Site command to connect the asynchronous site to the synchronous and primary sites.

To connect to SiteA:

symstar -cg train125 connect –site SiteA

 

To connect to SiteB:

symstar -cg train125 connect –site SiteB

 

   5. [   ]    Shut down ALL host applications at the current workload site (SiteB) using devices in the Star composite group being switched.

Task 2:     Halt the composite group

                       

   1. [   ]    Once all applications are shut down, type the symstar –cg CompositeGroupName halt command to halt Star replication for the group.

CAUTION:   The halt operation write disables all devices in the composite group at all sites. Ensure no applications are using the devices at any site before executing this command.

To halt composite group train125:

 

symstar -cg train125 halt

 

Output similar to the following is displayed:

 

A Star Halt operation is in progress for composite group train125. Please wait...

 

Halt ......................................................... Started

. . .

Halt ......................................................... Done

 

Task 3:     Switch the workload to the primary workload site

                       

   1. [   ]    Login to a control host at the primary workload site (SiteA).

   2. [   ]    Type the symstar –cg CompositeGroupName switch –site SynchronousTargetSite command to switch the workload back to the primary workload site.

To switch the workload for composite group train125 to SiteA:

 

symstar -cg train125 switch -site SiteA

 

Output similar to the following is displayed:

 

Switch_SiteA ................................................ Started

. . .

Switch_SiteA ................................................ Done

 

Note:  When the switch operation completes, devices in the Star composite group are Read/Write enabled at the new workload site and may be used by hosts at that site.

Task 4:     Protect the workload site using SRDF/Star

                       

You can protect either of the other two sites in the Star configuration.

In this example, protection is being set for both SiteB from SiteC.

   1. [   ]    From the workload site (SiteA), type the symstar –cg CompositeGroupName connect ‑site Site command to connect the workload site to the specified site.

To connect to SiteB:

symstar -cg train125 connect -site SiteB

 

To connect to SiteC:

symstar -cg train125 connect -site SiteC

 

   2. [   ]    Type the the symstar –cg CompositeGroupName protect ‑site Site command to protect the workload site to the specified site.

To protect SiteB:

symstar -cg train125 protect -site SiteB

 

To protect SiteC:

symstar -cg train125 protect -site SiteC

 

   3. [   ]    Type the symstar –cg CompositeGroupName enable command to enable SRDF/Star protection.

To enable SRDF/Star protection for composite group train125:

symstar -cg train125 enable

 

   4. [   ]    Type the symstar –cg CompositeGroupName query command to display the protection status of the composite group.

To query composite group train125:

symstar -cg train125 query

 

Output similar to the following is displayed:

 

Site Name                                     : SiteA

 

Workload Site                                 : SiteA

1st Target Site                               : SiteB

2nd Target Site                               : SiteC

 

Composite Group Name                          : train125

Composite Group Type                          : RDF1

 

Workload Data Image Consistent                : Yes

System State:

  {

  1st_Target_Site                             : Protected

  2nd_Target_Site                             : Protected

  STAR                                        : Protected

  Mode of Operation                           : Concurrent

  }

 

. . .