I do a LOT of PTFs and spoken to many of the fine folks at IBM re PTFs
and the process.
First off it has been stated that MANY PTFs simply require an IPL. The
objects being replaced simply cannot be updated at any other time as
they are always in use or otherwise locked. A claim of 90% of PTFs can
be applied immediately doesn't align with what I see. I suppose it's
possible in fact but with all the pre and co requisite PTFs all it takes
is one PTF in the 'set' to require an IPL and the other PTFs are stuck
so effectively all the PTFs require an IPL.
I have heard several times that using *IMMDLY (Immediate if possible,
Delayed to IPL when mandatory) Is NOT recommended for any PTF Groups
including CUMEs. It's essentially impossible to read every cover letter
and deal with all the special instructions. Failure to follow the
special instructions can mean many things, not the least of which is
that many of the PTFs that APPEAR to be applied are not active until an
action is taken, frequently the action is to IPL (which I find annoying!)
I do concur with other comments that if you are not provided sufficient
time for backups, PTFs, and other maintenance then having an HA system
is near mandatory. Clearly NOT doing PTFs and proper saves is just a
system crash looking for a bad time to occur. If time is so short when
you DO get a window that any problems push you into being considered an
outage that also is 'living on the edge'. Also consider making your
load source disk an SSD, this will 'enhance PTF apply performance.'
Generally I do like load and run Temp and SAVE 22. Run for perhaps 2 or
3 months. Then perm apply all and SAVE 22. Then repeat as necessary.
- Larry "DrFranken" Bolhuis
On 6/4/2014 11:56 AM, Steinmetz, Paul wrote:
Management would like to minimize the IPL, PTF, and system save downtimes.
HA/DR Is out of the question.
Currently, I try to IPL Production every 2 months for PTF apply along with a system save.
The IPL and system save will probably go to 6 months or as needed.
90% of PTFs can be applied immediately without an IPL, however IBM does not recommend immediate apply for more than a single PTF.
Applying a large amount of PTFs immediately has caused issues in the past.
Permission has been granted for the PTF immediate apply, but I'm weary from previous issues.
Any thoughts from the group.
IBM i Systems Administrator
Pencor Services, Inc.
462 Delaware Ave
Palmerton Pa 18071