As time marches on the size of our Performance Toolkit FCXTREND file
gets larger and larger. I can't seem to figure out how to "trim" this
file, so that (perhaps) only a few weeks or months data is kept
(depending on the system's purpose). How is that done?
You can just remove the oldest part of the file by using
- either COPYFILE with the 'FROM nn' option (means you temporarily
need disk space for both the original and the new file)
- or XEDIT (no additional disk space needed since the original file
can be erased before writing the pruned one back, but the original data
must fit into the machine's virtual storage).
Since I no longer have access to 'my' VM systems I cannot provide an
actual EXEC for doing it automatically, but the implementation is easy.
However, the above methods are crude insofar as they don't distinguish
between the different trend record types: one might want to delete the
detail records for specific users and/or I/O devices after just a few weeks,
but keep others a bit longer, and delete the records with summary system
data only after several years. So I have since written an FCXTREND
MODULE for a colleague who asked for such a facility. The module
allows specifying the rules for deleting specific types of trend file
records
in an FCONX TRDPRUNE control file.
If you're interested I'll ask him to send you the package for testing, and
if there's a general need it could also be made available on the download
page. However, while I wouldn't mind maintaining the code, analyzing
and fixing bugs without access to a z/VM system can be very tedious,
so better assume you have to use it 'as is'.
Eginhard Jaeger
