Resynchronizing the vFiler unit

You can resynchronize your original vFiler unit with the currently activated disaster recovery vFiler unit before bringing up the original vFiler unit. This method not only saves you from deleting the original vFiler unit and creating a new vFiler unit, but also does not require a baseline transfer (involving a large amount of data), which would otherwise occur between the new vFiler unit and the disaster recovery vFiler unit.

Before You Begin

You can resynchronize the vFiler unit if the following prerequisites are met:

The storage elements for the vFiler unit are only volumes (traditional or FlexVol) and not qtrees.
The source and destination vFiler units contain identical volumes.
The size of volumes on the source and the destination vFiler units is the same.
The vFiler unit from which you are updating is activated.
The original vFiler unit is not in the process of migration.
If new storage elements have been added to a disaster recovery activated vFiler unit, make sure that the newly added storage elements exist on the original storage system also.

Considerations

Attention:

On the storage system on which you are resynchronizing the original vFiler unit, protect any volumes that have the same names as volumes on the disaster recovery vFiler unit.

If a volume with the same name exists, the volume is automatically added and initialized for SnapMirror transfers from the disaster recovery vFiler unit. Any existing data on the newly added volume is lost.

If you want to delete old Snapshot copies after executing the vfiler dr resync command, you must first release them by using the snapmirror release command. If you fail to do this and Snapshot copies are deleted, then further snapmirror updates will fail to synchronize. See the na_snapmirror(1) man page for more information on snapmirror commands.

Steps

Ensure that the original vFiler unit you are resynchronizing is in a stopped state.
If not, enter the following command to stop the vFiler unit: vfiler stop vfilername
On the original storage system, enter the following command:vfiler dr resync [-l authinfo] [-a alt-remote, alt-local] [-c secure][-s] dr_vfilername@disaster_recovery_filer
authinfo is the authentication information specified in the username:password format. username is the login name of the administration host on the disaster recovery storage system and password is the password for that user name. If you do not specify the authentication information in the vfiler dr resync command, you are prompted for it when you run the command.

alt-remote is the alternate host name or IP address of the source (the disaster recovery storage system, in this case).

alt-local is the alternate host name or IP address of the destination (the original storage system, in this case).

-c enables you to use the secure command channel. This is used only in the vfiler dr commands that interact with the remote storage system.

-s enables you to set up a synchronous SnapMirror relationship between the source and destination storage systems.

dr-vfilername is the name of the disaster recovery vFiler unit that is currently in the activated state.

disaster_recovery_filer is the name of the storage system on which the currently activated disaster recovery vFiler unit exists.
Note:
- The vfiler dr resync command resynchronizes all storage elements that belong to the disaster recovery vFiler unit, including the volumes that were added to the disaster recovery vFiler unit after it was activated.
- The vfiler dr resync command also sets the incremental update interval from the source to the destination to be once every 3 minutes. Three minutes is the default setting. If you want to change the default setting, edit the etc/snapmirror.conf file as described in the the Data ONTAP Data Protection Online Backup and Recovery Guide.
- When you run the vfiler dr resync command on the disaster recovery vFiler unit to resync it with the original vFiler unit, you do not need to specify the -l, -a, and -s options. The values stored when the vfiler dr configure command was run (for a baseline transfer) to back up the original vFiler unit are used.
After the resync operation is complete, enter the following command on the storage system on which the original vFiler unit exists to check the status of the vFiler unit that was resynchronized: vfiler status -r original_vfilername
The original vFiler unit will be in a stopped, DR backup state. This is because the vfiler dr resync command does not activate the vFiler unit on resynchronizing. The vFiler unit continues to behave like a backup disaster recovery vFiler unit until you use the vfiler dr activate command to reactivate it.

Reinstate the disaster recovery vFiler unit on the disaster recovery storage system.

If the storage elements for the vFiler unit are...	Then...
Only volumes	On the disaster recovery storage system, enter the following command: `vfiler dr resync [-l authinfo] [-a alt-remote, alt-local] [-c secure] [-s] original_vfilername@original_filer`
qtrees	On the disaster recovery storage system, destroy the disaster recovery vFiler unit by entering the following command on the disaster recovery host storage system:`vfiler destroy vfilername` `vfilername` is the name of the original vFiler unit. On the disaster recovery storage system, re-create the disaster recovery vFiler unit.