About replication tunables
If you are using Resiliency Platform Data Mover to replicate your data across data centers, you have the option to tune some replication parameters to optimize the performance and scalability of the replication.
Resiliency Platform Data Mover replicates data from the protected virtual machines at the source data center to the target disks at target data center. The Replication Gateway component of Veritas Resiliency Platform is a staging server that aggregates and batches data from multiple virtual machines during replication. The staging storage on the Replication Gateway component of Veritas Resiliency Platform consists of two sections:
Reserve storage: Replication Gateway allocates a certain part of the staging storage disk to each of the protected virtual machine. This part of the staging storage is called reserve storage.
Shared pool: This part of the staging storage is shared among all the virtual machines.
Following are the three parameters for Replication Gateway that you can tune to optimize the Recovery Point Objective (RPO), replication performance, and scalability:
Update set: Before sending data to the target Replication Gateway, the source Replication Gateway implements a data optimization technique and creates a set of data. This set of data collected over a period is called an update set.
Replication Frequency: The period set to delimit and cut the update set is called replication frequency. Once an update set is cut, it gets scheduled for transfer to the target Replication Gateway.
Quota per Veritas Replication Set: The space reserved for each virtual machine in the reserve storage is called quota per Veritas Replication Set.
Table:
Tunable type | Change impact |
|---|---|
Quota per Veritas Replication Set (Quota-per-CG) | Scale (number of virtual machines protected by the Replication Gateway) |
size of update set (Update-set-size) | Performance (local deduplication), compression, RPO) |
Replication frequency | RPO for all the resiliency groups configured on the gateway |
The following formulae are used to link above replication tunables:
Reserve storage = number of virtual machines * Quota per Veritas Replication Set
Number of update sets = Quota per Veritas Replication Set / size of update set. The space for these many update sets is always reserved on the gateway.
You can tune the Quota-per-CG, update-set-size, and replication-frequency using the klish menu commands. See Klish menu options for Replication Gateway.