[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: rollback after software upgrade

On Tue, Jul 27, 2010 at 02:45:27AM +0200, Michael wrote:
> (i think you wanted to write "didn't" here ?)
> Wouldn't it be funny to ask developers for a downgrade converter :)
> It's an interesting question if there will be any 'standard' configuration syntax some day (maybe XML based?) and if up- and downgrades can convert them rather easily then, both hither and forth...

XML does not help anything.  It is just something that lets you store a
tree of config in a flat text file.  Nothing more.  The meaning of the
tree is still a problem.  Anyone that thinks XML solves all config
parsing problems and makes files underversal and supported clearly has
no idea what XML is.  That would make Microsoft very happy however.

A downgrade quite simply requires a time machine.  After all the
developer has to write support for converting a future format into a
current format when you downgrade.  The new version has the ability to
upgrade old versions to new, and that is of course tested.  It does not
have the ability to convert back (and to what version)?  At least in
debian packages, it is the package being installed that is responsible
for any conversions, not the one being removed, so on a downgrade the
newer package doesn't do the conversion, and it would be the only one
that could know how to do it (although it would probably have very little
testing, if it was done at all).

Len Sorensen

Reply to: