Creating SnapLock volumes

SnapLock is an attribute of the containing aggregate

Although this guide uses the term "SnapLock volume" to describe volumes that contain WORM data, in fact SnapLock is an attribute of the volume's containing aggregate. Because traditional volumes have a one-to-one relationship with their containing aggregate, you create traditional SnapLock volumes much as you would a standard traditional volume. To create SnapLock FlexVol volumes, you must first create a SnapLock aggregate. Every FlexVol created in that SnapLock aggregate is, by definition, a SnapLock volume.

Creating SnapLock traditional volumes

SnapLock traditional volumes are created in the same way a standard traditional volume is created, except that you use a -L <license_attribute> parameter with the vol create command. If a specific license is already enabled, there is no need to specify a compliance or enterprise attribute. However, when creating a volume, if both SnapLock Compliance and SnapLock Enterprise licenses are enabled, use the compliance or enterprise attribute to differentiate between licenses.

Verifying volume or aggregate status

You can use the vol status command to verify that the newly created SnapLock volume or aggregate exists. The following example displays vol status output, where the attribute of the SnapLock volume is in the Options column.

sys1> vol status

      Volume State      Status            Options

        vol0 online     raid4, trad       root

     wormvol online     raid4, trad       no_atime_update=on,

                                          snaplock_compliance

Creating SnapLock aggregates

SnapLock aggregates are created in the same way a standard aggregate is created, except that you use the -L parameter with the aggr create command. However, when creating an aggregate, if both SnapLock Compliance and SnapLock Enterprise licenses are enabled, use the compliance or enterprise attribute to differentiate between licenses.

SnapLock write_verify option

Data ONTAP provides a write verification option for SnapLock Compliance volumes: snaplock.compliance.write_verify. When this option is enabled, an immediate read verification occurs after every disk write, providing an additional level of data integrity.

Note
The SnapLock write verification option provides negligible benefit beyond the advanced, high-performance data protection and integrity features already provided by NVRAM, checksums, RAID scrubs, media scans, and double-parity RAID. SnapLock write verification should be used where the interpretation of regulations requires that each write to the disk media be immediately read back and verified for integrity.

SnapLock write verification comes at a performance cost and may affect data throughput on SnapLock Compliance volumes.