To restore a local storage instance after a node failure, run a script to rebuild the AMPs. Until the AMPs are rebuilt, data is maintained in fallback rows on the other AMPs.
If you are using EBS storage (r5 instance types), replace the EBS volumes before running the tdc-rebuild script.
The following command options are available with the tdc-rebuild script.
| Command Option | Description |
|---|---|
| -w |
|
| -t | changes the interval between display of rebuild progress messages from the default value of 4 seconds. Append this option with the number of seconds you want to elapse between status messages. For example, type -wt 20 to display status every 20 seconds. |
| Ctrl-c |
|
| -c | Cancels the rebuild process completely if it has started |
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At the command prompt, type one of the following commands:
- tdc-rebuild to run in interactive mode
- tdc-rebuild -w to run in non-interactive mode
-
Enter the Vantage super user (dbc) password and press Enter.
The script lists the AMPs that are rebuilt. For example:
FATAL AMPs are: AMP NodeId Cluster State ---- ------ ------- ------- 0 1-01 0 FATAL** 1 1-01 1 FATAL** 2 1-01 2 FATAL** 3 1-01 3 FATAL**
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When prompted to rebuild the AMPs, type one of the following commands:
- y to continue with the rebuild process
- n to stop the process and not alter the database
For example:Rebuild these AMPs? (Y/N): y *** Stopping Teradata to initialize pdisks --- Initialized pdisk /dev/pdisk/dsk0 --- Initialized pdisk /dev/pdisk/dsk1 --- Initialized pdisk /dev/pdisk/dsk2 --- Initialized pdisk /dev/pdisk/dsk3 *** Restarting Teradata to contine after initializing pdisks --- Booting FATAL AMPs --- Initiating AMP rebuilds 17:22:07 Background rebuild started, log into LOGAMP_0 17:22:07 Background rebuild started, log into LOGAMP_1 17:22:07 Background rebuild started, log into LOGAMP_2 17:22:07 Background rebuild started, log into LOGAMP_3 --- Rebuilds running Wait for rebuilds complete? (Y/N): n #
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If running in interactive mode, do one of the following when prompted whether to wait for the rebuilds to complete:
Option Actions To finish the rebuild without further interaction - Type y.
To finish the rebuild based on your continued input - Type n.
The script displays progress messages and then stops.
- Type #tdc-rebuild to restart the script.
- Enter the Vantage super user (dbc) password and press Enter.
- Repeat the preceding two sub-steps each time the script stops until the rebuild finishes.
The following output indicates rebuild completion.--- AMP rebuilds completed *** Restarting Teradata to set rebuilt AMPs online --- Rebuild complete