Performing SRDF R1/R2 Swap Using SYMCLI

 

Topic

Managing SRDF

Selections

Select SRDF management tool: Managing SRDF using Solutions Enabler SYMCLI

Select SRDF using SYMCLI task: Basic SRDF Operations

Select an SRDF task: Swapping R1/R2 Device Personalities

 

Contents

Perform a R1 <-> R2 swap. 4

About this procedure. 4

Task 1:  Enable dynamic SRDF in the Symmetrix array. 4

Task 2:  Verify which devices are SRDF swap-capable. 5

Task 3:  Swap the RDF devices. 6

 


 

Perform a R1 <-> R2 swap

About this procedure

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

·     EMC® Solutions Enabler Symmetrix® SRDF® Family CLI Product Guide

·    EMC Solutions Enabler Symmetrix Array Management CLI Product Guide

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

This procedure describes the steps to swap personality between the source (R1 devices at SiteA) and the target (R2 devices at SiteB) located at separate Symmetrix sites.

These instructions use the Solutions Enabler SYMCLI command line interface to manage devices by a device group. The user should be familiar with the concepts of SRDF, and have some experience using Solutions Enabler SYMCLI commands before attempting this procedure.

About dynamic swaps

Dynamic swap allows you to swap the RDF personality of the RDF device designations of a specified device group.

·        The source R1 devices become target R2 devices, and

·        The target R2 devices become source R1 devices.

 

Swaps using dynamic RDF are faster, but must be enabled in your configuration. You must also have one of the following license configurations:

·        An SRDF license and a Configuration Manager license

·        An SRDF license and a Configuration Manager license, and the devices to be swapped are not dynamic RDF-enabled in your Symmetrix configuration

·        An SRDF license and dynamic RDF is enabled in your Symmetrix configuration

 

Dynamic swap restrictions

Dynamic swap is not supported:

·        For Enginuity version 5669 and higher systems where the R2 device is larger than the R1 device.

·        For concurrent RDF devices.

·        Since Enginuity Version 5568, the dynamic RDF configuration state of the Symmetrix must be enabled for the swap operation. Dynamic RDF-capable devices are configured as one of three types: RDF1 capable, RDF2 capable, or both. Dynamic R1/R2 Swap capability requires that the devices be configured as both to initiate a swap.

·        When swapping the RA group personalities that engage ESCON directors in a FarPoint connection, be aware that FarPoint buffer settings cannot be adjusted using symconfigure command. If your FarPoint buffers are set to customized parameters other than default values, an EMC representative will need to be called to adjust the buffer settings after the swap has taken place.

 

Task 1:     Enable dynamic SRDF in the Symmetrix array

   1. [   ]    Type the symcfg list –v command.

   2. [   ]    Check the output to verify that the Dynamic RDF Configuration State is set to Enabled.

The next step varies depending on whether Dynamic RDF is enabled:

·        If Dynamic RDF is already enabled, skip to Task 2:

·        If Dynamic RDF is not enabled, proceed to Step 3. [   ]

 

   3. [   ]    Use a text editor (NotePad, vi) to create a text file containing the following command line:

set symmetrix dynamic_rdf = enable;

 

In the following example, vi is used to create a text file named set_sym.cmd.

vi set_sym.cmd

set symmetrix dynamic_rdf = enable;

 

   4. [   ]    Type the symconfigure commit –sid SID –file FileName command to execute the command file on the local site:

To enable dynamic SDRF on SID 605 using text file set_sym.cmd:

symconfigure –sid 605 commit –file set_sym.cmd

 

   5. [   ]    On a host connected to the remote array, repeat Steps 3. [   ] and 4. [   ] to enable dynamic SRDF on the remote array.

Task 2:     Verify which devices are SRDF swap-capable

                       

   1. [   ]    Type the symrdf list –dynamic command to display RDF devices configured as RDF swap capable.

Use the symrdf list -dynamic -R1 syntax to display RDF devices configured as R1 swap capable.

Use the symrdf list -dynamic –R2 syntax to display RDF devices configured as R2 swap capable.

Use the symrdf list -dynamic –both syntax to display RDF devices configured as both R1 and R2 swap capable.

   2. [   ]    Examine the output and determine which devices you want to swap.

Note:   Only devices in “legal” states can be swapped. The following table lists which states are legal for the swap operation.

Restrictions

·        When swapping source and target attributes I/O is not allowed to the R1 device, but I/O is allowed to the R2 devices.

·        If the devices are not mapped to the user host, you must enable the SYMAPI_CTRL_OF_NONVISIBLE_DEVS behavior parameter in the options file.

·        Beginning with Enginuity Version 5671, dynamic swap can be performed on devices in SRDF/Asynchronous mode.

·        Dynamic swap cannot be performed for SRDF/A devices that are enabled for consistency protection or if the SRDF/A session is actively copying.

The table below shows how swapping the R1/R2 designation of the RDF devices impacts the state of your stored data.

Task 3:     Swap the RDF devices

                       

Type the symrdf -g DgName swap [-bcv|-all] [-refresh R1|R2] command to swap the SRDF personality of the designated SRDF devices.

·        Use the -bcv option to target just the BCV-associated devices for the swap action in the device group.

·        Use the -all option to target both BCV and standard devices.

·        Use no option (neither –bcv nor –all) to target just the standard devices.

 

The refresh action indicates which device does not hold a valid copy of the data before the swap operation begins. If you determine that the R2 holds the valid copy, the action of refresh R1 will obtain a count of the tracks and will mark the tracks that are different on the R1 to refresh from the R2 to the R1device. The result will be the reverse if you choose to refresh R2 as the option.

 

·        Use the –refresh R1 option to mark the source (R1) devices to refresh from the remote mirror.

·        Use the -refresh R2 option to mark the target (R2) devices to refresh from the remote mirror.

 

To swap the R1 designation of the associated BCV RDF1 devices in a device group named ProdGrpB and refresh any modified data on the current R1 side of these BCVs from their R2 mirrors:

 

symrdf -g ProdGrpB -bcv swap -refresh R1