What SnapLock is

SnapLock is an alternative to the traditional optical "write once, read many" (WORM) data. SnapLock is used for the storage of read-only WORM data.

SnapLock is a license-based, disk-based, open-protocol feature that works with application software to administer non-rewritable storage of data. The primary objective of this Data ONTAP feature is to provide storage-enforced WORM and retention functionality by using open file protocols such as CIFS and NFS. SnapLock can be deployed for protecting data in strict regulatory environments in such a way that even the storage administrator is considered an untrusted party. An example of such an environment is the broker or dealer market that is regulated by the U.S.Securities and Exchange Commission (SEC) rule 240.17a-4. Alternative configurations of SnapLock can be deployed for unregulated or more flexible regulated environments.

SnapLock provides special purpose volumes in which files can be stored and committed to a non-erasable, non-rewritable state either forever or for a designated retention period. SnapLock allows this retention to be performed at the granularity of individual files through standard open file protocols such as CIFS and NFS (versions 2, 3, and 4). The retention of these files is enforced by Data ONTAP, through which all the file protocols or administrative access to the data must pass.

• What SnapLock volumes are
  SnapLock volumes are of two types—SnapLock Compliance volume and SnapLock Enterprise volume.
• How SnapLock works
  The WORM data on SnapLock volumes are administered in the same way as regular (non-WORM) volumes. SnapLock volumes operate in WORM mode and support standard file system semantics. You can create data on a SnapLock volume and commit it to the WORM state by transitioning the file from a writable state to a read-only state.
• Issues in reverting to Data ONTAP 7.3 if you have SnapLock volumes
  SnapLock is disabled in the first release of Data ONTAP 7.3. Therefore, if you revert from a later release in the Data ONTAP 7.3 release family, any SnapLock Compliance or SnapLock Enterprises license that has been installed on the later release will either be disabled or your storage system will halt.
• Hardware platforms supported for SnapLock
  SnapLock is exclusively a licensed feature of Data ONTAP and is supported on almost all NetApp hardware platforms except for V-Series systems. SnapLock is not a "software only" solution; it is part of an integrated hardware and software solution.
• How to license SnapLock
  SnapLock is a persistent property of both the SnapLock volumes and the files on SnapLock volumes. It is strictly enforced regardless of the state of the licensing. SnapLock requires a separate license. You need a license only for the creation of new SnapLock volumes and for the committing of files to the WORM state on SnapLock volumes.
• SnapLock support for AutoSupport
  If AutoSupport is enabled, the storage system sends AutoSupport messages to technical support. These messages include event and log-level descriptions. SnapLock volume state and options are included in the AutoSupport output.
• Creating SnapLock volumes
  You can create SnapLock traditional volumes or SnapLock FlexVol volumes. Before you create a SnapLock FlexVol volume, however, you must create an aggregate with SnapLock as an attribute of that aggregate.
• SnapLock Compliance write verification option
  You can use the SnapLock Compliance write verification option when each write operation to the disk media must be immediately read back and verified for integrity.
• How SnapLock Compliance meets WORM data requirements
  SnapLock Compliance prevents anyone, including the system administrator, from destroying or altering files, volumes, or aggregates before they reach their expiration date.
• What the ComplianceClock is
  The ComplianceClock is a secure time base that prevents compliant data from being tampered with. The ComplianceClock makes it impossible to change the system clock to prematurely alter or remove the compliant data.
• When to use the ComplianceClock
  You use the ComplianceClock for performing various SnapLock operations.
• Initializing the ComplianceClock feature
  You must initialize the ComplianceClock feature if you want to enforce WORM data retention on SnapLock volumes. If the ComplianceClock is not initialized, you cannot delete the files after their expiry date, even on SnapLock Enterprise volumes.
• Viewing the ComplianceClock time
  You can view the ComplianceClock time to verify that it is synchronization with the system clock.
• How the ComplianceClock stays synchronized with the system clock
  The ComplianceClock, which is implemented in software, can lag behind the system clock and must realign itself with the system clock periodically.
• SnapLock ComplianceClock considerations with qtree SnapMirror
  The ComplianceClock on a SnapLock qtree can be transferred with a qtree SnapMirror copy to either another SnapLock Compliance qtree or a SnapLock Enterprise qtree. However, the ComplianceClock might not be transferred to a non-SnapLock qtree.