What can go wrong if msi installations will be patched with xcopy?

[Gottfried Schipfer]

Hi,

I try to use as much as possible MSI based installations for our software
products.
Now colleagues have implemented a patch tool which updates installed
products (1st install by msi) with an batch-file.
They update several files, kill running processes, stop/restart services,
execute sql scripts and register com servers with this tool.
I tried to find arguments why we should avoid this xcopy patching tool, but
they argumented that it works! Only repair or msi update is not possible
anymore otherwise it would undo the xcopy patch.

Can somebody help me to find the right arguments, why this will/can be
harmful.

Kind regards,
Gottfried

[Wilson, Phil]

Repair may be an issue, yes, because it's really difficult to prevent a
repair, and the repair may undo the changes. You can't prevent right-click
Repair on an MSI file. There are several entrypoints that cause a repair and
you can't be sure you've stopped them all. If you have components shared
with other products (and that includes MS redists) a repair of that product
can cause a repair in yours. So experimentally it seems to work, but that
doesn't really mean that "it works" unless you have covered every scenario
that applies, and I guarantee they haven't. So your concerns are valid. MSI
files are updated by upgrades and patches, not by xcopy. There may not be a
document that says "don't do this" but that's because a list of the things
that you shouldn't do would be endless. I wouldn't be surprised if somebody
says "well .NET is supposed to be xcopy anyway". Well, no....

Other issues:
1. You can't remove the changes (you can with a patch) if you screw up some
customer. Unless they do a repair maybe, what irony.
2. I've seen cases where a later major upgrade caused a request for the
original install CD because the upgrade sees that the file on disk is not
the one being upgraded, so it requests the install CD to restore it, a
repair before upgrade.
3. They've reinvented the wheel, writing code for stuff that MSI already
does. This might be the typical developer's syndrome, which is "well I'm a
developer I know how to do this, and I can't be bothered to figure how MSI
works anyway, so I'll write a bunch of code".
--
Phil Wilson
The Definitive Guide to Windows Installer
http://www.apress.com/book/view/1590592972

"Gottfried Schipfer" <schi...@gmx.at> wrote in message
news:ec54b$4b0c26ff$557c6f40$10...@news.inode.at...

[Gottfried Schipfer]

Thanks for your clear arguments!
I'll try to convince my colleagues and I'll come forward with a clean
solution so that the xcopy patching can be stopped.

Kind regards,
Gottfried

"Wilson, Phil" <ph...@wonderware.nospam.com> schrieb im Newsbeitrag
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