Note
The recommended method for enabling FastResync on a volume with a version 20 DCO is to use the vxsnap
prepare
command as described in Preparing a volume for DRL and instant snapshots.
You need a Veritas FlashSnapTM or FastResync license to use this feature.
FastResync performs quick and efficient resynchronization of stale mirrors. It also increases the efficiency of the VxVM snapshot mechanism when used with operations such as backup and decision support. See Administering volume snapshots and FastResync for more information.
There are two possible versions of FastResync that can be enabled on a volume:
See Adding a version 0 DCO and DCO volume, and Preparing a volume for DRL and instant snapshots for more information on version 0 and version 20 DCO volumes respectively.
If the existing volume was created in a previous release of VxVM, and it has any attached snapshot plexes or it is associated with any snapshot volumes, follow the procedure given in Upgrading existing volumes to use version 20 DCOs.
By default, FastResync is not enabled on newly created volumes. Specify the fastresync=on
attribute to the vxassist
make
command if you want to enable FastResync on a volume that you are creating.
Note It is not possible to configure both Persistent and Non-Persistent FastResync on a volume. Persistent FastResync is used if a DCO is associated with the volume. Otherwise, Non-Persistent FastResync is used.
To turn FastResync on for an existing volume, specify fastresync=on
to the vxvol
command as shown here:
# vxvol [-g
diskgroup
] set fastresync=on
volume
Note To use FastResync with a snapshot, FastResync must be enabled before the snapshot is taken, and must remain enabled until after the snapback is completed.