Owner's manual

ServerNet Nomadic Disk Overview

ServerNet Nomadic Disk User’s Guide—425485-001

1-5

Logically Switching a Database

While a physical switch changes the connection of a device from one node to another

node, a logical switch allows the backup node to access a database after a physical

switch occurs. Logical switching fixes naming inconsistencies that arise when a

database is moved to a node with a different node name and node number.

Supported Database Products

Enscribe contains features that support logical switching. Before performing a logical

switch, review the following consideration:

Enscribe alternate-key files that reside on a Nomadic volume must not be created with a

node specified as in this example:

> FUP ALTER $DATA.B.C, ALTFILE (0,\ABC.$DATA.B.C0)

Before switching a Nomadic volume to a backup node for the first time, change the

Enscribe alternate-key file so that a node name is not specified. For example:

> FUP ALTER $DATA.B.C, ALTFILE (0,$DATA.B.C0)

For more information about the Enscribe environment, refer to the Enscribe

Programmer’s Guide.

Unsupported Database Products

The following are not supported by the ServerNet Nomadic Disk subsystem:

•

NonStop Transaction Manager/MP (TM/MP)

•

Compaq NonStop SQL/MP and products that depend on it such as distributed

systems management (DSM)/Tape Catalog and distributed systems

management/software configuration manager (DSM/SCM)

•

Open System Services (OSS)

•

Storage Management Foundation (SMF)