Planned 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: Planned switch: Workload site to Asynchronous target site

 

 

Contents

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

About this procedure. 4

Task 1:  Halt host applications at the workload site that use the consistency group. 5

Task 2:  Halt the composite group. 5

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

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

 


 

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

This procedure describes the steps to gracefully shut down the primary workload site (SiteA) and switch the SDRF/Star protection to the asynchronous target site (SiteC).

This procedure shows the switch from SiteA to SiteC and the subsequent protection of data with SRDF/Star.

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 at the workload site that use the consistency group

                       

   1. [   ]    Log in to the control server for the workload site (SiteA).

   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                                     : 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

  }

 

Last Action Performed                         : Enable

Last Action Status                            : Successful

Last Action Timestamp                         : 06/15/2010_10:03:28

 

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

  }

. . .

 

   3. [   ]    Note the value of “System State“ in the output.

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

Task 2:     Halt the composite group

                       

   1. [   ]    From the workload site, once all applications have been 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 site to the asynchronous target site

                       

   1. [   ]    Login to a control host at the asynchronous target site (SiteC).

   2. [   ]    Type the symstar –cg CompositeGroupName switch –site AsynchronousTargetSite command to switch the workload to the asynchronous target site.

To switch the workload for composite group train125 to SiteC:

 

symstar -cg train125 switch -site SiteC

 

Output similar to the following is displayed:

 

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

. . .

Switch_SiteC ................................................ 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 new workload site using SRDF/Star

                       

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

In this example, protection is being set up to SiteB from SiteC.

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

To connect SiteC to SiteB:

symstar -cg train125 connect -site SiteB

 

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

To protect SiteB:

symstar -cg train125 protect -site SiteB

 

   3. [   ]    Type the symstar –cg CompositeGroupName query command to display the new workload site and protection status of the composite group.

To query 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

  }

. .