Re: Anyone tried SystemTap with the latest RHEL5 Beta refresh

[Vara Prasad <prasadav at us dot ibm dot com>]

Frank Ch. Eigler wrote:

> Hi -
>
>  
>
> > fche wrote:
> > [...]
> >    
> >
> > > Unfortunately, other customers prefer that systemtap's loose
> > > dependencies (particularly, the kernel-debuginfo) not be installed by
> > > default, even if they choose an "install everything" option at the
> > > anaconda screens.  [..]
> > >      
>
> varap wrote:
>
>  
>
> > O.k, before i think of a way to satisfy both the needs i need to 
> > understand the objection of the other group.
> >    
>
>  
>
> > The objection of other customers to not to install debuginfo package is 
> > it because of wasted disk space due to large size of debuginfo package 
> > or time to install or something else.
> >    
>
> All those, plus the manual way in which RHEL debuginfo packages are at
> present published.
>  
Well if my memory serves well Elena's plan for RHEL 5 is not to go 
through this manual step. She tried her best to eliminate for RHEL 4 but 
it didn't work due to some reasons of packaging i am not aware but the 
assurance she had from the packaging team was in RHEL 5 it will be 
available as part of the install media. If you want I can reopen the 
issue tracker for this.

I am fine to install only kernel debuginfo package as a compromise and 
module debuginfo package doesn't need to be installed although we should 
also make it available on the install media.

>  
>
> > I am assuming kernel debuginfo is considered a dependency for
> > SystemTap, am I right?
> >    
>
> It is a loose dependency, in that the RPM does not list it as such
> (any more), and that it is theoretically possible to run some scripts
> without kprobes, and thus without dwarf data.
>  
How many of our example scripts and tapset probe points i can use 
without debug info package, my guess not much, so how a customer can 
even experiment if they can't use the examples system comes with.

>  
>
> > What is the point of installing a package that doesn't work due to
> > lack of dependencies?
> >    
>
> Among other reasons, it simplifies the task of the person overseeing
> an initial installation.  
Well if a person wants a simplified install of limited packages you can 
go through custom install and choose the packages you like, that is what 
normally i do if i don't care for the default install.

> They may not want systemtap as such, merely
> use the "everything that is on this CD" option as a time-saver.
>  

As mentioned above for RHEL 5 we need to make debuginfo package readily 
available as part of the install media, if we have any chance of getting 
feedback from real end users (not just developers). I personally think 
the default install should have SystemTap package and required 
dependencies installed but for those who don't want that we should let 
them opt out.  Competition is already installing the full package as 
part of the default install, if we make it difficult to use we will loose.

I agree for FC installation we could avoid installing debuginfo package 
as the space for those small setups is significant.

> - FChE
>