Enabling FastResync on a volume

The recommended method for enabling FastResync on a volume with a version 20 DCO is to use the vxsnap prepare command.


To use this feature, you need a FastResync license.

FastResync quickly and efficiently resynchronizes stale mirrors. When you use FastResync with operations such as backup and decision support, it also increases the efficiency of the VxVM snapshot mechanism.

You can enable the following versions of FastResync on a volume:

By default, FastResync is not enabled on newly-created volumes. If you want to enable FastResync on a volume that you create, specify the fastresync=on attribute to the vxassist make command.


You cannot configure Persistent and Non-Persistent FastResync on a volume. If a DCO is associated with the volume, Persistent FastResync is used. Otherwise, Non-Persistent FastResync is used.

To turn on FastResync for an existing volume, specify fastresync=on to the vxvol command as follows:

# vxvol [-g diskgroup] set fastresync=on volume

To use FastResync with a snapshot, you must enable FastResync before the snapshot is taken, and it must remain enabled until after the snapback is completed.

More Information

Preparing a volume for DRL and instant snapshots

About volume snapshots


Adding a version 0 DCO and DCO volume

Upgrading existing volumes to use version 20 DCOs

Preparing a volume for DRL and instant snapshots