Volume 2, Number 56 - July 26, 2002 Archives - IT Jungle

Generating a Unique Identifier

July 26, 2002 Timothy Prickett Morgan

Hey, Ted:

I just read your article, “Using Timestamps as Unique Keys,” in the July 17 issue of Midrange Guru, OS/400 Edition.

There might be a better way of creating a unique ID, one that doesn’t require retries. It’s the GENUUID API and/or MI built-in.

Universal Unique Identifier (UUID) is supposed be a totally unique ID, even across all the machines in the entire world. I’m assuming that in reality this is 100 percent true, but I wouldn’t worry about it.

Here’s some code that I’ve had stashed away:
```
H option(*NoSrcStmt) DftActGrp(*No)                       
                                                               
D UUIDTemplate    ds                                          
D   BytesProv                   10u 
```
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Restore a Single IFS Directory

July 26, 2002 Timothy Prickett Morgan

Hey, Joe:

I backed up my entire Integrated File System (IFS) using option 21 (Entire System) from the GO SAVE menu. Now I want to restore just one IFS directory called /test1, not the entire IFS.

How do I do it?

— Alex

The answer here is to use OS/400’s Restore (RST) command. This is a fairly easy command to run, but there are one or two quirks to watch out for as you do it. Here’s my drill for restoring a single directory to the IFS.

First, put the tape (or tapes) from the full system backup containing the
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