Why doesn't df reflect paritition change?

[drake at drake.almaden.ibm.com]

In article <HENKEL%NEPJT.90Sep12132202 at nepjt.ncsuvx.ncsu.edu> henkel at nepjt.ncsu.edu (Chuck Henkel) writes:
>
>Context: RS/6000 Model 320
>
>I used the Logical Volume Manager under smit to add a free logical
>partition (LP) to the /u filesystem.
>However, df still claims that /u has a total of 4MB. What's the deal?

I imagine that you used the "wrong" command and/or SMIT selection to
accomplish what you wanted to do.  Extending a file system involves two
separate operations at the lowest level:

1.  Adding additional logical partitions to the logical volume in question,
    and
2.  Twiddling data in the filesystem on the logical volume to tell it that
    the space is there.  

There is a command that will do both of these together, and there is also
a command for just doing (1).  This latter command would be useful if you
were using a logical volume for a purpose other than a filesystem.  I 
expect that you ran this latter command, not the former.  

Fear not; if you now run the former command, it will do the right thing.
No harm will become you (I've made the same misteak, too).

To get to the command you want, run SMIT, then select "Physical and Logical 
Devices", then "File Systems" (NOT Logical Volume Manager), then 
"Add/Change/Show/Delete File Systems", then "Journaled File Systems", 
then "Change / Show Characteristics of a Journaled File System",
then select the filesystem you want to mess with, then type the new size
of the file where asked and press Enter.  Done.

Or type "chfs -a size=nnnnn".  


Sam Drake / IBM Almaden Research Center 
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