CentOS - Jun 2006 - RPM install vs. NFS mount and code versioning

The ongoing discussion regarding Perl modules and RPMs, prompted me  
to post an issue I am currently facing.  I support a development team  
that uses various third party tools, some free, some not, some of  
which are installed via RPMs, and some that are not.  The development  
cycle is 18-24 months long, and then there are many years of support  
(continuing engineering) after that, for which the various versions  
of the tools need to be available.  There are a few dozen engineers  
on the project.

Let say that I want to install SuperTool V1.1, and it's available to  
install only via RPMs.  After thorough testing/qualification on one  
workstation, I need to install it on the few dozen workstations,  
which is straightforward but possibly time consuming (and you have to  
deal with workstations that may be down when you are doing the  
installs).  When V1.2 comes out, I can again test it on one  
workstation, and then deploy it on the remaining workstations.  But  
what if I there is a bug, and we need to test it against the old  
version of the tool?  With RPMs, it is cumbersome to go back and  
forth between versions.  Contrast that with a tar based install,  
where I can untar the tool in a directory that includes a version  
number in the path, and then automount that directory to all the  
workstations.  There is only one install, and I can easily move back  
and forth among the various versions.

Now I understand the benefits of RPMs, but when it comes to  
supporting tool vendors, dealing with tar based installations and  
using automounts really simplifies things.  I am thinking about  
installing the RPM based tools on one system, and then copying the  
entire install tree to a NAS and automount it.  I know this is not  
ideal, but I can't think of a better solution.  Any thoughts from the  
members of this list?  Have you tried to solve similar problems in  
the past?  If so, how did you do it?

Alfred

On Thu, 2006-06-01 at 22:30, Alfred von Campe wrote:
> Now I understand the benefits of RPMs, but when it comes to  
> supporting tool vendors, dealing with tar based installations and  
> using automounts really simplifies things.  I am thinking about  
> installing the RPM based tools on one system, and then copying the  
> entire install tree to a NAS and automount it.  I know this is not  
> ideal, but I can't think of a better solution.  Any thoughts from the  
> members of this list?  Have you tried to solve similar problems in  
> the past?  If so, how did you do it?
One group of developers here tries to check everything that
might be version-related into CVS with everything tagged
at release points.  That means anyone can start with a
fairly bare machine and a build script can check out all the
tool and source versions needed to re-create anything they
have ever done.  A side effect of this is that the
developers never have to build the deployed executables - they
just give the tags or a build script to the operators who
build and install the final versions, ensuring that the
build can be repeated.  A different group always uses the
same build machine and has had an assortment of problems
like forgotten tweaks being lost during upgrades or when
restoring after disk failures.  Due to the nature of their
product they rarely have to work with old revisions and
it's probably a good thing.  If there is another incarnation
of the 'dedicated build machine' concept, I'd probably do
it as a virtual machine under VMware and archive copies of
the things before any changes to the tool set so it would
be possible to revive exact copies of old versions.

-- 
  Les Mikesell
   lesmikesell at gmail.com