Best practices for setting up replication
|Article:HOWTO22198|||||Created: 2010-01-29|||||Updated: 2010-01-11|||||Article URL http://www.symantec.com/docs/HOWTO22198|
Set up replication according to the following best practices:
Create one RVG for each application, rather than for each server. For example, if a server is running three separate databases that are being replicated, create three separate RVGs for each database. Creating three separate RVGs helps to avoid write-order dependency between the applications and provides three separate SRLs for maximum performance per application.
Create one RVG per disk group. Creating one RVG per disk group enables you to efficiently implement application clustering for high availability, where only one RVG needs to be failed over by the cluster package. If the disk group contains more than one RVG, the applications using the other RVGs would have to be stopped to facilitate the failover. You can use the Disk Group Split feature to migrate application volumes to their own disk groups before associating the volumes to the RVG.
Lay out the SRL appropriately to support the performance characteristics needed by the application. Because all writes to the data volumes in an RVG are first written to the SRL, the total write performance of an RVG is bound by the total write performance of the SRL. For example, dedicate separate disks to SRLs and if possible dedicate separate controllers to the SRL.
Use the same names for the data volumes on the Primary and Secondary nodes. If the data volumes on the Primary and Secondary have different names, you must map the name of the Secondary data volume to the appropriate Primary data volume.
The vradmin utility creates corresponding RVGs on the Secondary of the same name as the Primary. If you choose to use the vxmake command to create RVGs, use the same names for corresponding RVGs on the Primary and Secondary nodes.
Associate a DCM to each data volume on the Primary and the Secondary if the DCMs had been removed for some reason. By default, the vradmin createpri and vradmin addsec commands add DCMs if they do not exist.
If you are setting up replication in a shared environment, before you do so, determine the node that is performing the most writes by running the vxstat command on each node for a suitable period of time, and then after you set up replication, specify that node as the logowner.
Article URL http://www.symantec.com/docs/HOWTO22198