Redirecting the ToolTalk Database Server

You can redirect both database host machines and the file system partitions.

• Redirecting a database host machine allows a ToolTalk client to physically access ToolTalk data from a machine that is not running a ToolTalk database server.

• Redirecting a file system partition allows a ToolTalk database to logically read and write ToolTalk data from and to a read-only file system partition (for example, a CD-Rom) by physically accessing a different file system partition. Redirecting a file system partition also is done if a system administrator wants all ToolTalk databases to reside on a single local partition instead of one per local partition, which is the default.

Redirecting the Host Machine

When you redirect a database host machine, a ToolTalk client can physically access ToolTalk data from a machine that is not running a ToolTalk database server. To redirect the host machine, you need to map the hostnames of the machines the ToolTalk client is to access. On the machine running the ToolTalk client that is making the database query:

1. Create a hostname_map file.

   For example:

   
   

   # Map first host machine oldhostname1 newhostname1 # Map second host machine oldhostname2 newhostname2

   where oldhostname is the name of the machine the ToolTalk client needs to access and newhostname is the name of a machine that is running the ToolTalk database server.

2. Store the file in the same location at which the ToolTalk Types databases are stored.

   The map files have the same order of precedence as the ToolTalk Types databases (see tt_type_comp(1).

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   Note - A file defined in the TT_HOSTNAME_MAP environment variable has a higher precedence than the map in the user database.

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   The map file is read into a ToolTalk client when the client makes a tt_open call. For detailed information on host redirection see hostname_map(4).

Redirecting the File System Partition

When you redirect a file system partition, a ToolTalk database can logically read and write ToolTalk data from and to a read-only file system partition by physically accessing a different file system partition. To redirect a file partition, you need to map the partitions to where the ToolTalk database will write. On the machine running the ToolTalk database server:

1. Create a partition_map file.

   For example:

   
   

   # Map first partition /cdrom /usr # Map second partition /sr0/export/home /export/home

   maps the read-only partition /cdrom to /usr, a read-write partition; and maps the read-only partition /sr0/export/home to /export/home, a read-write partition.

2. Store the map file in the same location at which the system ToolTalk Types databases are stored.

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   Note - A file partition defined in the TT_PARTITION_MAP environment variable has a higher precedence than the file partition defined in this map file.

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   The map file is read when the ToolTalk database server is started, or when the database server receives a USR2 signal. For detailed information on partition redirection see partition_map(4).