1.4 Examples of DFS Management Contexts

This section describes multiple examples of DFS management contexts. The following icons represent eDirectory containers and objects in the examples.

Figure 1-3 Icons for eDirectory Containers and Objects

1.4.1 A Single DFS Management Context

In the following example, a single DFS management context is shown by a shaded box.

Figure 1-4 A Single DFS Management Context

Feature

Description

The management context is defined at the eDirectory container called west.company (ou=west.o=company).

Junctions can point to any supported volume in the management context.

Two replica servers each host an instance of the VLDB service for the management context. Its VLDB maps the location of the volumes at all levels in the subtree defined by the west.company eDirectory container.

Volume objects in the east.company (ou=east.o=company) subtree are not in a management context in this example, so it is not possible to create a junction to any supported volumes in this part of the tree.

1.4.2 Multiple DFS Management Contexts in Different Subtrees

In the following example, two management contexts in different subtrees are shown by shaded boxes.

Figure 1-5 DFS Management Contexts in Different Subtrees

Feature

Description

The management context defined at west.company (ou=west.o=company) functions in a different subtree than the management context defined at east.company (ou=east.o=company).

Replica sites for each context must reside within their respective management context.

Junctions can point to any supported volumes in either of the management contexts.

Move volume and split volume jobs can be defined only for source and target volumes within the same management context.

Two replica servers each host an instance of the VLDB service for the west.company management context. The VLDB maps the location of the volumes at all levels in the subtree defined by the west.company eDirectory container. In this example, the replicas are located in different organizational units in the subtree, but they could be in the same one.

A single replica server hosts the VLDB service for the east.company management context. Its VLDB maps the location of the volumes at all levels in the subtree defined by the east.company eDirectory container.

1.4.3 Multiple DFS Management Contexts in the Same Subtree

In the following example, a second management context is added at a lower level in the same subtree. The two management contexts are shown by shaded boxes in the After figure.

Figure 1-6 Adding a DFS Management Contexts at a Lower Level in the Subtree

Feature

Description

The management context is defined at west.company (ou=west.o=company). One of its two replica servers resides in the subtree legal.west.company where you want to create a second DFS management context. You must delete this replica from the west.company management context before you create the DFS management context for legal.west.company.

If the replica in legal.west.company is the only replica server for west.company, you must create a second replica server in a different subtree of west.company, synchronize the VLDB on the second replica server, delete the replica in legal.west.company, then create the second DFS management context.

The management context defined at west.company (ou=west.o=company) does not contain legal.west.company (ou=legal.ou=west.o=company).

A single replica server hosts the VLDB service for the west.company management context. Its VLDB maps the location of the volumes at all levels in the subtree defined by the west.company eDirectory container, except for those volumes in the legal.west.company subtree. You can optionally add a second replica in the subtree, but not under the legal.west.company subtree.

Replica sites for each context must reside within their respective management context.

Junctions can point to any supported volumes in either of the management contexts.

Move volume and split volume jobs can be defined only for source and target volumes within the same management context.

The management context defined at legal.west.company (ou=legal.ou=west.o=company) functions independently of the management context defined above it.

A single replica server hosts the VLDB service for the legal.west.company management context. Its VLDB maps the location of the volumes at all levels in the subtree defined by the legal.west.company eDirectory container. You can optionally add a second replica in the legal.west.company subtree.

Volume objects in the east.company (ou=east.o=company) subtree are not in a management context in this example, so it is not possible to create a junction to any volumes in this part of the tree.

In the following example, a second management context is added at a higher level in the same subtree. The two management contexts are shown by shaded boxes in the After figure.

Figure 1-7 Adding a DFS Management Contexts at a Higher Level in the Subtree

Feature

Description

The management context is defined at legal west.company (ou=legal.ou=west.o=company). Its replica server is not affected by the management context you want to add at a higher level in the eDirectory tree.

Volume objects in the east.company (ou=east.o=company) subtree are not in a management context in this example, so it is not possible to create a junction to any volumes in this part of the tree.

The management context defined at west.company (ou=west.o=company) does not contain legal.west.company (ou=legal.ou=west.o=company).

A single replica server hosts the VLDB service for the west.company management context. Its VLDB maps the location of the NSS volumes at all levels in the subtree defined by the west.company eDirectory container, except for those NSS volumes in the legal.west.company subtree. You can optionally add a second replica in the subtree, but not under the legal.west.company subtree.

Replica sites for each context must reside within their respective management context.

Junctions can point to any supported volumes in either of the management contexts.

Move volume and split volume jobs can be defined only for source and target volumes within the same management context.

The management context defined at legal.west.company (ou=legal.ou=west.o=company) functions independently of the management context defined above it.

A single replica server hosts the VLDB service for the legal.west.company management context. Its VLDB maps the location of the volumes at all levels in the subtree defined by the legal.west.company eDirectory container. You can optionally add a second replica in the legal.west.company subtree.

The east.company subtree is not affected by the addition of a DFS management context in a different subtree even though it is at the same level in the tree.

In both of the same-subtree examples, if you delete the higher-level DFS management context (west.company), the VLDB service on its replica server (svr2.servers.west.company) is stopped and its VLDB is deleted. Any junctions that point to volumes in the deleted management context are broken. Deleting the west.company management context has no effect on the lower-level DFS management context at legal.west.company.

In both of the same-subtree examples, if you delete the lower-level DFS management context (legal.west.company), the VLDB service on its replica server (svr52.servers.legal.west.company) are stopped and its VLDB is deleted. The higher-level management context automatically expands to include the lower-level subtree. A VLDB repair adds the volumes in the subtree to the VLDB. When the repair is completed, junctions that point to volumes in the legal.west.company subtree continue to work normally.