Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF

STATUS MODES RDF S T A T E S
Sym RDF --------- ----- R1 Inv R2 Inv ----------------------
Dev RDev Typ:G SA RA LNK MDATE Tracks Tracks Dev RDev Pair
---- ---- -------- --------- ----- ------- ------- --- ---- -------------
80A4 0340 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A5 0341 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A6 0342 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A7 0343 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A8 0344 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80A9 0345 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
80AA 0346 R1:2 RW RW RW S..1. 0 0 RW WD Synchronized
2. Create an RDF1 type device group.
For example, the group name AsynDG.
On R1 side run the following command:
# symdg create AsynDG -type RDF1
On R2 side run the following command:
# symdg create AsynDG -type RDF2
3. All devices from the RDF (RA) group configuration are added to the device group for
SRDF/Asynchronous operation. For example, if the RDF group displayed in the symrdf list
is group number 2, then all devices in this RDF group must be managed together within one
device group for SRDF/Asynchronous operation.
# symld -g AsynDG addall -rdfg 2
4. Repeat steps 1 through 3 on every host that runs Serviceguard packages.
5. Query the device group to display the R1-to-R2 setup and the state of the SRDF/Asynchronous
device pairs.
# symrdf -g AsynDG query -rdfa
Here is a sample output from this command:
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 MDACE STATE
-------------------------------- -- ------------------------ ----- ------------
DEV001 80A4 RW 0 0 RW 0340 WD 0 0 S.... Synchronized
DEV002 80A5 RW 0 0 RW 0341 WD 0 0 S.... Synchronized
DEV003 80A6 RW 0 0 RW 0342 WD 0 0 S.... Synchronized
DEV004 80A7 RW 0 0 RW 0343 WD 0 0 S.... Synchronized
DEV005 80A8 RW 0 0 RW 0344 WD 0 0 S.... Synchronized
6. Set the device group to Asynchronous mode:
# symrdf -g AsynDG set mode async
7. You must enable consistency protection to ensure data consistency on R2 side for the
SRDF/Asynchronous devices in the device group.
# symrdf -g AsynDG enable
8. If the SRDF pairs are not in a Consistent state at this point, synchronize the data on the R2
side from the R1 side using the following command. The device state will be SyncInProg
until the Consistent status is reached.
# symrdf -g AsynDG establish
Here is a sample output after the RDF pairs are established:
Source (R1) View Target (R2) View MODES
-------------------------------- ------------------------ ----- ------------
18 Configuring an application in a Metrocluster solution