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Creating a custom replication policy

You can create a custom replication policy if the default policy for a relationship is not suitable. You might want to compress data in a network transfer, for example, or modify the number of attempts SnapMirror makes to transfer Snapshot copies.

About this task

The policy type of the replication policy determines the type of relationship it supports. The table below shows the available policy types.

Policy type

Relationship type

async-mirrorSnapMirror DR
vaultSnapVault
mirror-vaultUnified replication
strict-sync-mirrorSnapMirror Synchronous in the StrictSync mode (supported starting with ONTAP 9.5)
sync-mirrorSnapMirror Synchronous in the Sync mode (supported starting with ONTAP 9.5)
Tip
When you create a custom replication policy, it is a good idea to model the policy after a default policy.
Create a custom replication policy: snapmirror policy create -vserver SVM -policy policy -type async-mirror|vault|mirror-vault|strict-sync-mirror|sync-mirror -comment comment -tries transfer_tries -transfer-priority low|normal -is-network-compression-enabled true|false

For complete command syntax, see the man page.

Starting with ONTAP 9.5, you can specify the schedule for creating a common Snapshot copy schedule for SnapMirror Synchronous relationships by using the -common-snapshot-schedule parameter. By default, the common Snapshot copy schedule for SnapMirror Synchronous relationships is one hour. You can specify a value from 30 minutes to two hours for the Snapshot copy schedule for SnapMirror Synchronous relationships.

Example

The following example creates a custom replication policy for SnapMirror DR that enables network compression for data transfers:

cluster_dst::> snapmirror policy create -vserver svm1 -policy DR_compressed -type async-mirror -comment <q className="q">DR with network compression enabled</q> -is-network-compression-enabled true

Example

The following example creates a custom replication policy for SnapVault:

cluster_dst::> snapmirror policy create -vserver svm1 -policy my_snapvault -type vault

Example

The following example creates a custom replication policy for unified replication:

cluster_dst::> snapmirror policy create -vserver svm1 -policy my_unified -type mirror-vault

Example

The following example creates a custom replication policy for SnapMirror Synchronous relationship in the StrictSync mode:

cluster_dst::> snapmirror policy create -vserver svm1 -policy my_strictsync -type strict-sync-mirror -common-snapshot-schedule my_sync_schedule

After you finish

For vault and mirror-vault policy types, you must define rules that determine which Snapshot copies are transferred during initialization and update.

Use the snapmirror policy show command to verify that the SnapMirror policy was created. For complete command syntax, see the man page.