1.5 DST Components

There are four main components for Dynamic Storage Technology.

1.5.1 NCP Engine

The NCP Engine provides support for NCP clients and the main file copy engine for Dynamic Storage Technology. It provides the merged view for NCP users and Novell CIFS users. It supports the ShadowFS access for SMB/CIFS users.

1.5.2 Shadow Volume

Shadow Volume allows NCP users and Novell CIFS users to see a merged file-tree view of the primary file tree and shadow file tree.

1.5.3 ShadowFS

The Shadow File System (ShadowFS) works with Novell Samba and FUSE (File Systems in Userspace) to provide a merged view for SMB/CIFS users. It also allows Linux applications (such as Samba Server, PureFTP, and SSH) to see the merged view of the shadow volume.

IMPORTANT:Beginning in OES 2 SP3, Novell CIFS can be used instead Novell Samba. Novell CIFS does not require ShadowFS and FUSE. For information, see Novell CIFS.

ShadowFS uses FUSE to create a local mount point for each DST shadow volume in /media/shadowfs/shadow_volume_name. FUSE is an open source software package included in OES 2 Linux that is installed automatically when you install DST.

1.5.4 Policy Engine

The DST policy engine allows you to create, manage, and enforce policies for a shadow. There are two types of policies:

  • Global: The policy applies to every mounted shadow volume on the server. If global policies are set for a server where volumes are in a clustered pool, these policies must be set on every node in the cluster. For information about setting global policies, see Section 3.0, Installing Dynamic Storage Technology.

  • Volume: The policy applies only to a specified volume. Volume policies can be used for local or shared volumes. They should be used when volumes are in a clustered pool so that the policy easily follows the volume when the cluster resource fails over. For information, see Section 10.0, Creating and Managing Policies for Shadow Volumes.