Creating SnapLock destination volumes

What SnapLock volumes are

SnapLock volumes are Write-Once-Read-Many (WORM) volumes that you create for data you want to archive permanently. There are two types of SnapLock volumes:

SnapLock Compliance volume--for strict regulatory environments, such as SEC 17a-4 compliant environments
SnapLock Enterprise volume--for environments without regulatory restrictions.

For details about licensing and creating SnapLock volumes, see the Storage Management Guide.

Synchronous SnapMirror and SnapLock volumes

SnapLock Compliance volumes do not support synchronous SnapMirror. SnapLock Enterprise volumes do support synchronous SnapMirror.

SnapMirror options

You cannot replicate a non-SnapLock volume to a SnapLock Compliance volume. Nor can you replicate a SnapLock Enterprise volume to a SnapLock Compliance volume.

You can replicate a non-SnapLock volume to a SnapLock Enterprise volume. Note that the SnapMirror replication does not automatically perform WORM commits for files transferred in such a configuration. To perform WORM commits, you have to break the SnapMirror replication and perform the WORM commits on all transferred files, either manually or using a script.

You can also replicate a SnapLock Compliance volume or a SnapLock Enterprise volume to a non-SnapLock volume. There are no restrictions on this replication.

The following table summarizes the different SnapMirror replication options using SnapLock volumes.

	Destination volume type
Source volume type	Non-SnapLock	SnapLock Enterprise	SnapLock Compliance
Non-SnapLock	Allowed	Allowed	Not allowed
SnapLock Enterprise	Allowed	Allowed	Not allowed
SnapLock Compliance	Allowed	Allowed	Allowed

SnapLock destination volume restrictions

A SnapMirror destination volume created as a SnapLock Compliance volume has the following restrictions:

You cannot use the snapmirror resync command to return a former destination volume and resynchronize its content with the source.
Note
This restriction applies to volume SnapMirror relationships only. Resynchronization is supported for qtree SnapMirror relationships.
You cannot reinitialize a SnapLock Compliance destination volume because data on the volume cannot be changed. If you break the SnapMirror relationship between the source and destination volumes using the snapmirror break command, Data ONTAP prevents you from ever reestablishing the SnapMirror relationship with the same SnapLock Compliance destination volume.
You can initialize a new empty SnapLock Compliance destination volume.

A SnapMirror destination volume created as a SnapLock Enterprise volume is the same as a destination volume created for a non-SnapLock volume. You can perform all the same administrative tasks on a SnapLock Enterprise destination volume that you can perform on a non-SnapLock destination.

Qtree SnapMirror resync for SnapLock Compliance volumes

The SnapMirror resync command enables you to re-establish a broken SnapMirror relationship without a lengthy baseline transfer. Typically, this command locates the most recent Snapshot copy, discards any data written to the destination after that Snapshot copy, and begins to resynchronize content using the common Snapshot copies.

To support data integrity in a restrictive SnapLock Compliance environment, the resync operation saves all data that was written after the common Snapshot copy to a directory on the volume. The SnapMirror resync operation locates the most recent Snapshot copy, and saves any changes that occured prior to that Snapshot copy to an image and log file. These files are then stored in following directory on the SnapLock Compliance volume:

/etc/logs/snapmirror_resync_archive/volname_UUID_qtree

The image and log files are named dump_image_YYMMDD_HHMMSS, and dump_log_YYMMDD_HHMMSS, respectively.

Note
The retention period for image and log files is equal to the longest retention period of any data file in the data set. This ensures that the image and log files will not be deleted before the retention period has passed.

If the save operation fails for any reason, the resync transfer operation will not proceed.

For detailed information about the SnapMirror resync command, see Resynchronizing SnapMirror.

Creating a SnapLock Compliance SnapMirror relationship

To create a SnapMirror relationship from a SnapLock Compliance volume to a SnapLock Compliance destination volume, complete the following steps.

Note
This procedure assumes you have read about basic SnapMirror setup and you have experience with creating SnapMirror relationships. See Setting up a basic SnapMirror operation for a details about first-time SnapMirror setup.

Step	Action
1	On the administration host, create or edit the snapmirror.conf file on the destination system to specify the SnapLock Compliance volume source and destination. Example The following entry specifies asynchronous mirroring from vol1 of s_system and vol2 of d_system using the default replication arguments. s_system:vol1 d_system:vol2 - * * * *
2	On the destination system console, create the destination volume using the `vol create` command. Example vol create vol2 2 Caution Do not use the `vol create -L` command to create a SnapLock Compliance volume because volume SnapMirror cannot use it as a destination volume.
3	On the destination system console, mark the volume as restricted using the `vol restrict` command.
4	On the destination system console, create an initial complete (baseline) copy of the source on the destination and start the mirroring process using the `snapmirror initialize -L` command. Result After successfully completing the baseline transfer, Data ONTAP converts the destination volume to a SnapLock Compliance destination volume before bringing it online. Example snapmirror initialize -S s_system:vol1 -L d_system:vol2 Note After the destination volume is converted to a SnapLock Compliance destination volume, it will always be a SnapLock Compliance volume and cannot be changed.

Creating a SnapLock Enterprise SnapMirror relationship

Creating a SnapMirror relationship from a SnapLock Enterprise source volume to a SnapLock Enterprise destination volume is the same as creating a SnapMirror relationship for non-SnapLock Enterprise volumes. See Setting up a basic SnapMirror operation for a details about first-time SnapMirror creation.

Creating SnapLock destination volumes

What SnapLock volumes are

Synchronous SnapMirror and SnapLock volumes

SnapMirror options

SnapLock destination volume restrictions

Qtree SnapMirror resync for SnapLock Compliance volumes

Creating a SnapLock Compliance SnapMirror relationship

Example

Example

Result

Example

Creating a SnapLock Enterprise SnapMirror relationship