I've got a problem of not having the right mathematical formula. My
problem is that, when planning a new TSM data space for Log, Database,
or disk storage pool volume, I cannot figure out the maximum
size I can allocate. I'm using AIX 4.3.3.ML9 with TSM 4.2.2.8.

Step 1) Use the OS to create a Unix file system of the appropriate size
and characteristics. The Unix "df -k" command (allegedly) tells me how
big it is and how much space is in it:

Filesystem    1024-blocks      Free %Used    Iused %Iused Mounted on
/dev/kumquat      8781824   3008300   66%       18     1% /usr/local/kumquat

Step 2) Format it. The following calculations are from "TSM
Administrator's Reference". 3008300k/1024=2937m Rounding down to a
multiple of 4mb gives you 2936m. Adding 1 for overhead gives you 2937m.
However, specifying

dsmfmt -m -db /usr/local/kumquat/db12 2937

It formats for a long time and then abends with message:

Error writing file /usr/local/kumquat/db12, errno = 28

...which means, not enough space.

Where are my calculations going wrong? I can try to reduce the number a
few mb at a time and figure this out by trial and error, but this takes
literally DAYS of my time. So I usually guess at 98% and waste some
space. How can I really calculate this?

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu
============ "The World's Least Intuitive Operating System" ============
=============== -- from the cover of "Unix for Dummies" ================