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Managing files and subvolumes on Tandem systems can seem complex, especially when you need to move or rename large sets of files efficiently. This post breaks down practical steps to move files between subvolumes, rename subvolumes, and handle related tasks like extracting information from saveabend files. It also introduces useful tools like Garth and explains concepts such as HIGHPIN processes. Whether you are a system administrator or a developer working with Tandem NSK, this guide offers clear, actionable advice to simplify your workflow.
Moving Files Between Subvolumes on Tandem Systems
When working with Tandem systems, you might face the need to move all files from one subvolume to another. Unlike some systems, Tandem does not have a dedicated FUP MOVE command. Instead, you use the FUP RENAME command to achieve this.
How to Move All Files from One Subvolume to Another
Suppose you want to move every file from the subvolume `$DATA00.FIRST` to `$DATA00.SECOND`. You can use the following command:
```
FUP RENAME $DATA00.FIRST. , $DATA00.SECOND.
```
This command renames all files matching the wildcard `*` in the `FIRST` subvolume to the `SECOND` subvolume. It effectively moves the files because the file names now point to the new subvolume.
You can replace the wildcard `*` with any specific file-name template if you want to move only certain files.
This method is as effective as renaming the entire subvolume `FIRST` to `SECOND`.
Important Notes
Ensure no processes are actively using the files during the rename to avoid conflicts.
This approach works well for batch operations, saving time compared to moving files individually.
Renaming a Subvolume on Tandem Systems
Tandem systems do not provide a direct command to rename a subvolume. However, the FUP RENAME command described above serves as a practical workaround. By renaming all files from one subvolume to another, you effectively rename the subvolume.
For example, moving all files from `$DATA00.FIRST` to `$DATA00.SECOND` renames the subvolume `FIRST` to `SECOND` in practice.
Extracting Preliminary Information from a SAVEABEND File
SAVEABEND files contain critical information about system failures or abnormal terminations. Extracting preliminary data helps diagnose issues quickly.
How to Extract Information
At the Inspect prompt, use this command:
```
--INFO SAVEFILE FILE ZZSA3126
```
Replace `ZZSA3126` with the actual saveabend file name. This command provides an overview of the saveabend file contents, helping you identify the cause of the failure or gather data for further analysis.
Understanding Garth: A High-Level Debugging Tool
Garth is a symbolic, high-level debugging tool designed for Tandem NSK systems and various UNIX platforms like Sun-OS and Solaris. It combines features from popular debuggers such as GDB and Crunch, along with new utilities.
Key Features of Garth
Works on live systems via TCP-IP and on processor images (dumps).
Based on GNU Debugger (GDB) and Tcl/Tk scripting language.
Highly flexible and extensible; users can write custom scripts.
Originally developed by Hieu Tran during work on Native Mode 1.
Garth simplifies low-level debugging by providing a user-friendly interface and powerful scripting capabilities. For more details, visit the Garth home page.
What is HIGHPIN and Why Does It Matter?
Each process running on a CPU in a Tandem system has a unique Process Identification Number (PIN). Before the Dxx release, the system supported up to 256 processes per CPU, with PINs ranging from 0 to 255.
Changes Introduced by the Dxx Release
The number of processes per CPU increased beyond 256.
Processes with PINs greater than 255 are called HIGHPIN processes.
Processes with PINs 0 to 255 are called LOWPIN processes.
Why This Matters for Developers
Programs may require changes to run correctly with HIGHPIN processes because:
HIGHPINs use 16-bit integers.
LOWPINs use 8-bit integers.
This difference affects how process IDs are stored and handled in software. Ensuring compatibility with HIGHPINs is essential for applications running on newer Tandem systems.
Practical Tips for Managing Tandem Systems
Use FUP RENAME to move or rename files across subvolumes efficiently.
Always verify no active processes are using files before renaming.
Extract saveabend file information early to speed up troubleshooting.
Explore tools like Garth to improve debugging workflows.
Update software to support HIGHPIN processes if running on newer Tandem releases.
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