Before you run sysinit, you should understand the following concepts.
Globally Distributed Objects
Globally Distributed Objects, (GDOs) are binary files of structured data that are kept consistent across all nodes and vprocs in a Teradata Database system. GDOs typically store system settings and configuration information that is shared by all nodes of the system.
Sysinit initializes several Teradata Database GDOs.
Depending on the state of the DBS Control Record, GDOs, and on the current configuration when System Initializer is run, sysinit prompts for certain information, such as the hash function to use for row distribution among AMPs, and the type of language support required. For information on these prompts, see Running System Initializer.
Configuration maps define the current and new configuration of the Teradata Database system vprocs. A configuration map:
- Stores the identification and status of each vproc in the Teradata Database system
- Identifies the AMPs that constitute each AMP cluster
- Identifies each PE and its associated host
The Teradata Database system contains two configuration maps:
- The current configuration map describes the current arrangement and status of vprocs in the Teradata Database system
- The new configuration map describes changes and additions to the configuration
Sysinit can create a new configuration map and keep or revise a current map. For new configuration maps initialized by sysinit from the current configuration, the current configuration can retain one AMP and all existing PEs. The new configuration can retain one or all AMPs and all existing PEs.
New Versus Previously Initialized Systems
First-Time Initialization for New Systems
When used to initialize a new Teradata Database system, sysinit initializes a configuration that includes all the vprocs defined in a vprocconfig GDO.
On a new, uninitialized, Teradata Database system (or on a corrupted Teradata Database system whose configuration map cannot be read), sysinit creates a full configuration based on the vprocconfig GDO. All vprocs are set to an online, operational state. If a problem exists with any vproc, then a 0 PE, 1 AMP configuration is created. If a full configuration was created, then you are given options later for selecting a particular configuration for the new and old config maps.
Previously Initialized Systems
On a previously initialized Teradata Database system, sysinit retains the current configuration map and prompts you to do one of the following:
Sysinit will destroy all user and dictionary data currently in the Teradata Database system.
- Retain the current configuration in the new configuration map
- Select a different configuration for the current and the new configuration maps
Sysinit may reset the configuration settings stored in various GDOs and normally set using various system utilities to default values for the new version of Teradata Database.
If you need to run sysinit on an existing system, first collect information from the following to ensure that customized settings can be restored and set as required after the sysinit:
- Control GDO Editor (ctl)
- DBS Control
- TDN Tuner (tdntune)
- Vproc Manager
System Control Files:
- vconfig.out file
- UDF libraries (optional)