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Configuring SRDF for VMAX Replication

To configure Symmetrix Remote Data Facility (SRDF) for VMAX Replication, complete the following process:

  1. Find and choose the director pairs to be used for creating SRDF group between two Symmetrix arrays
  2. Add a Dynamic SRDF Group
  3. Create a Dynamic SRDF Pair
  4. Add Target devices for TimeFinder Snap/Clone/Mirror/VP Snap Operations
  5. Run symrdf establish command to copy R1 data to R2 devices
  6. Ensure that R1-R2 pair is in synchronized
  7. Enable device level write pacing for SRDF asynchronous mode

Find and Choose the Director Pairs to Use for Creating an SRDF Group Between Two Symmetrix Arrays

In the following example output, the director 07H on Symmetrix array 64 is connected to director 01H and 02H on Symmetrix Array 58.

-bash-4.1# symsan -sanrdf -sid 64 -dir all list
Symmetrix ID: 000192605964
Flags Remote
--- ------- ---------------------------------
Dir Lnk
Dir CT S Symmetrix ID Dir WWN
--- --- --- ------------ --- ----------------
07H GO C 000198700258 01H 50000973F00409C0
07H GO C 000198700258 02H 50000973F00409C4
08H GO C 000198700258 01H 50000973F00409C0
08H GO C 000198700258 02H 50000973F00409C4

Legend:
Director:
(C)onfig : S = Fibre-Switched, H = Fibre-Hub
G = GIGE, - = N/A
S(T)atus : O = Online, F = Offline, D = Dead, - = N/A

Link:
(S)tatus : C = Connected, P = ConnectInProg
D = Disconnected, I = Incomplete, - = N/A
-bash-4.1# symsan -sanrdf -sid 58 -dir all list

Symmetrix ID: 000198700258

Flags Remote
--- ------- ---------------------------------
Dir Lnk
Dir CT S Symmetrix ID Dir WWN
--- --- --- ------------ --- ----------------
01H GO C 000192605964 07H 50000972085D31D8
01H GO C 000192605964 08H 50000972085D31DC
02H GO C 000192605964 07H 50000972085D31D8
02H GO C 000192605964 08H 50000972085D31DC

Legend:
Director:
(C)onfig : S = Fibre-Switched, H = Fibre-Hub
G = GIGE, - = N/A
S(T)atus : O = Online, F = Offline, D = Dead, - = N/A

Link:
(S)tatus : C = Connected, P = ConnectInProg
D = Disconnected, I = Incomplete, - = N/A

Add a Dynamic SRDF Group

In the following example, a new dynamic SRDF group is added.

It adds dynamic SRDF group 1 on local symmetrix array (000192605964) and dynamic SRDF group 1 on remote symmetrix array(000198700258) with label as dyngrp1 and directors of both sides of replication.

-bash-4.1# symrdf addgrp -sid 000192605964 -rdfg 1 -label dyngrp1 -dir 07H -remote_rdfg 1 -remote_sid 000198700258 -remote_dir 01H

Execute a Dynamic RDF Addgrp operation for group
'dyngrp1' on Symm: 000192605964 (y/[n]) ? y
SSuccessfully Added Dynamic RDF Group 'dyngrp1' for Symm: 000192605964

Create a Dynamic SRDF Pair

Before creating a dynamic SRDF pair, identify source and target volumes for replication and set device attributes as R1/R2/RDF-Capable from Unisphere.

After identifying source and target volumes, create a file containing R1 and R2 Symmetrix device identifier. R1 and R2 devices are specified in two columns and each SRDF pair on separate lines.

-bash-4.1# cat devicepairs.txt
023C 047A
023D 047B

The symrdf createpair command creates new SRDF pairs from the list of devices in the device file. The R2 devices are invalidated with this create pair example and the SRDF pairs become members of SRDF group 1. The invalidate option (-invalidate [R1|R2]) marks the R1 devices or R2 devices in the list to be the invalidated target for a full device copy once the SRDF pairs are created.

-bash-4.1# symrdf createpair -file devicepairs.txt -sid 000192605964 -rdfg 1 -type r1 -invalidate r2 "g RDFGroup1 "rdf_mode <sync/async>

Execute an RDF 'Create Pair' operation for device file
'dyngrp1' (y/[n]) ? y

An RDF 'Create Pair' operation execution is in progress for device
file 'dyngrp1'. Please wait...

Create RDF Pair in (5964,001)....................................Started.
Create RDF Pair in (5964,001)....................................Done.
Mark target device(s) in (5964,001) for full copy from source....Started.
Devices: 023C-023D in (5964,001).................................Marked.
Mark target device(s) in (5964,001) for full copy from source....Done.

The RDF 'Create Pair' operation successfully executed for device
file 'dyngrp1'.

This will create a device group named RDFGroup1 and add source devices in that group.

Add Target devices for TimeFinder Snap/Clone/Mirror/VP snap operations

Target devices to be used for creating “TimeFinder Snap/Clone/Mirror/VP Snap” on both sites must be added to this group.

For example:

  1. To add local BCV devices to RDFGroup1.

    -bash-4.1# symbcv -g RDFGroup1 add dev 202 -sid 64
    Note: If adding remote TDEVs use following command

    symdg -g RDFGroup1 add dev 0DA3 -tgt

  2. To add remote BCV devices to RDFGroup1.

    -bash-4.1# symbcv -g rdfg2-64 add dev 481 -rdf
    Note: If adding remote TDEVs use following command
    symdg -g rdfg2-64 add dev 0DA3 -rdf -tgt

  3. Verify that required devices are added to device group RDFGroup1.

    -bash-4.1# symdg show RDFGroup1

Run the symrdf establish Command to Copy R1 Data to R2 Devices

The symrdf establish command copies R1 data to R2 devices. The "invalidate r2 option from the previous command invalidated the R2 devices, a step that is usually carried out during a full establish operation. Consequently, you do not need the "full option. The invalidate step is not repeated, regardless of whether you use the "full option or not. If subsequently you re-establish or restore the dynamic SRDF pairs, omitting or including the "full option will affect how the copy occurs (either an incremental copy or a full copy, respectively). The output below says “Incremental Establish” because the "full option was omitted. However, because all tracks on the R2 devices were previously invalidated, the result is a full copy of all R1 tracks to the R2 tracks.

-bash-4.1# symrdf -g RDFGroup1 establish

Execute an RDF 'Incremental Establish' operation for device
group 'RDFGroup1' (y/[n]) ? y

An RDF 'Incremental Establish' operation execution is
in progress for device group 'RDFGroup1'. Please wait...

Suspend RDF link(s).......................................Done.
Resume RDF link(s)........................................Started.
Resume RDF link(s)........................................Done.

The RDF 'Incremental Establish' operation successfully initiated for
device group 'RDFGroup1'.

Ensure That R1-R2 Pair Is in Synchronized State

Ensure that R1-R2 pair is in synchronized state by running the following command:

-bash-4.1# symrdf -g RDFGroup1 query

Device Group (DG) Name : RDFGroup1
DG's Type : RDF1
DG's Symmetrix ID : 000192605964 (Microcode Version: 5876)
Remote Symmetrix ID : 000198700258 (Microcode Version: 5876)
RDF (RA) Group Number : 1 (00)

Source (R1) View Target (R2) View MODES
-------------------------------- ------------------------ ----- ------------
ST LI ST
Standard A N A
Logical T R1 Inv R2 Inv K T R1 Inv R2 Inv RDF Pair
Device Dev E Tracks Tracks S Dev E Tracks Tracks MDAE STATE
-------------------------------- -- ------------------------ ----- ------------

DEV001 023C RW 0 0 RW 047A WD 0 0 C.D. Synchronized
DEV002 023D RW 0 0 RW 047B WD 0 0 C.D. Synchronized

Total -------- -------- -------- --------
Track(s) 0 0 0 0
MB(s) 0.0 0.0 0.0 0.0

Legend for MODES:

M(ode of Operation) : A = Async, S = Sync, E = Semi-sync, C = Adaptive Copy
D(omino) : X = Enabled, . = Disabled
A(daptive Copy) : D = Disk Mode, W = WP Mode, . = ACp off
(Consistency) E(xempt): X = Enabled, . = Disabled, M = Mixed, - = N/A

Enable Device-Level Write Pacing for SRDF Asynchronous Mode

SRDF/A write pacing extends the availability of SRDF/A by preventing conditions that result in cache overflow on both the R1 and R2 sides.

#symrdf -sid 64 -rdfg 1 activate -rdfa_devpace

Execute an RDF 'Device Pacing Activate' operation for
RDF group '1' (y/[n]) ? y

An RDF 'Device Pacing Activate' operation execution is in progress for
RDF group 7. Please wait...

Activate SRDF/A Device-level Write Pacing on (5964,007) ..........Done.

The RDF 'Device Pacing Activate' operation successfully executed for
RDF group 1.