Sample setup showing how to take snapshots using the IBC messaging facility


Sample setup showing how to take snapshots using the IBC messaging facility
Prev	Example: Using the IBC messaging facility to take snapshots	Next

Primary host name: VVRPRI

vvr_dg	Disk Group
vvr_rvg	Primary RVG
vvr_dv01	Primary data volume #1 (Assigned drive letter E: NTFS Formatted)
vvr_dv02	Primary data volume #2 Assigned drive letter F: NTFS Formatted)
vvr_rep_log	Primary Replicator Log volume

Secondary host name: VVRSEC

vvr_dg	Disk Group
vvr_rvg	Secondary RVG
vvr_dv01	Secondary data volume #1
vvr_dv02	Secondary data volume #2
vvr_rep_log	Secondary Replicator Log volume

The above example makes the following assumptions that the Secondary is attached and connected. The time-out values for various vxibc command options are arbitrarily chosen.

To take a snapshot of the Secondary at an application-defined consistency interval

Prepare the volumes on Secondary using the following command:
```
vxassist -g vvr_dg prepare vvr_dv01
vxassist -g vvr_dg prepare vvr_dv02
```
To be able to create disk group split friendly snapshots, make sure that the snapshots are created on separate disks that do not contain the RVG objects.
On the Secondary, wait for the IBC message from the Primary whose application is registered by the name APP1. Indicate that the vxrvg snapshot command should be executed on receiving this message using the command:
```
vxibc -g vvr_dg -R 300 regrecv APP1 vvr_rvg "vxrvg
 -g vvr_dg -f-P snap snapshot vv_rvg"
```
The command prompt is not available, unless the IBC message is received from the Primary or receive time-out (after 300 seconds) has occurred.
On Primary, put the application into a consistent state after making sure that data is flushed from the cache to volumes using the command:
```
vxrvg dismount vvr_rvg
```
Send an IBC message to the Secondary, informing it that the application level consistency is achieved at the Primary and that the Secondary can now take a snapshot:
```
vxibc -g vvr_dg regsend APP1 vvr_rvg
```
On receiving this message, the Secondary side vxibc regrecv command that is awaiting this message in Step 2 comes out after creating the snapshots using the snapshot command.
You can now use the snapshot volumes on the Secondary for performing any tasks.