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The first step in creating an RDS is creating its Primary RVG. VVR enables you to create a Primary RVG of an RDS using the vradmin createpri command.
The vradmin createpri command enables you to associate existing data volumes and the Storage Replicator Log (SRL) to the Primary RVG. The vradmin createpri command performs the following operations:
Note
Specify the volume set name in the command, not the names of each component volume. Specifying the component volume name causes the command to fail.
VVR does not support RAID-5 volumes, that is, volumes with usage type raid5 are not supported. Data volumes must be of usage type gen or fsgen. However, data volumes can be configured on hardware-based RAID-5 disks.
Dirty Region Logs (DRLs) are not needed with VVR because VVR uses the SRL to recover volumes, not the DRLs. If any of the data volumes or the SRL has a DRL, the vradmin createpri command removes the DRL before the data volume is associated to the RVG.
By default, the vradmin createpri command adds DCMs to the data volumes, if they have not already been added. The vradmin createpri command creates the DCM of an appropriate default size based on the size of the volume and mirrors the DCM by default. To create and add a DCM of a size that is different from the default, see Associating a Data Change Map to a data volume. Run the vradmin createpri command after you have associated the DCMs of the required size to the data volumes.
The -nodcm option when used with the vradmin createpri command associates data volumes to the RVG but does not add DCMs to the data volumes.
If you want to associate additional volumes to the RVG after creating the RVG, use the vradmin addvol command. See Associating a volume to a Replicated Data Set.
Prerequisites for creating a Primary RVG of an RDS
The data volumes and SRL must exist on the Primary. If the data volumes and SRL do not exist on the Primary, create them. To associate a volume set to the RVG, the volume set must exist on the Primary.
The SRL cannot be a volume set or a component volume of a volume set.
The data volumes and SRL must be started. If the data volumes and SRL are not started, start them. When a data volume is started, its state is active.
The data volumes used by the application must exist in the same RVG. Include the data volumes used by the application in the same RVG.
To create a Primary RVG of an RDS
Issue the following command on the host on which you want to create the Primary RVG:
# vradmin -g diskgroup createpri rvgname \ dv01_name,dv02_name... srl_name
The argument rvgname is the name of the RVG to be created.
The argument dv01_name,dv02_name,... is a comma-separated list of the names of the data volumes to be associated to the RVG. Each item can be an independent data volume name, or the name of a volume set. To associate a volume set to the RVG, specify the name of the volume set, not the names of the individual component volumes.
Note
In previous releases, component volumes could be associated directly to an RVG. In this release, the volume set itself is associated to the RVG, enabling VVR to verify consistency between the volume sets on the Primary and the Secondary RVGs. The vradmin createpri command fails if a component volume of the volume set and the volume set itself are each specified for an RVG.
The argument srl_name is the name of the SRL to be associated to the RVG.
Use -nodcm option if you do not want DCMs to be added to the data volumes. By default, DCMs are added automatically.
This example shows how to create a Primary RVG hr_rvg in the disk group hrdg, which contains the data volumes hr_dv01 and hr_dv02, and the volume hr_srl that is to be used as the SRL. This example automatically adds DCMs to the data volumes.
# vradmin -g hrdg createpri hr_rvg hr_dv01,hr_dv02 hr_srl
This example shows how to create a Primary RVG hr_rvg in the disk group hrdg, which contains the volume set hr_vset, the data volumes hr_dv01 and hr_dv02, and the volume hr_srl that is to be used as the SRL.
# vradmin -g hrdg createpri hr_rvg hr_dv01,hr_dv02,hr_vset \ hr_srl
If the volume set includes the component volumes hr_vsetdv01 and hr_vsetdv02, these volumes are associated to the RVG hr_rvg. This example automatically adds DCMs to the data volumes, including the component volumes hr_vsetdv01 and hr_vsetdv02.