[Mageia-discuss] Suggestions for the ISO

Sun Nov 7 00:54:52 CET 2010

Olivier Thauvin a écrit :
+> * andre999 (andr55 at laposte.net) wrote:
+>    
+>> Luca Berra a écrit :
+>>      
+>>> On Wed, Nov 03, 2010 at 08:16:22PM +0100, Olivier Thauvin wrote:
+>>>        
+>>>> * andre999 (andr55 at laposte.net) wrote:
+>>>>          
+>>>>> Donald Stewart a écrit :
+>>>>>            
+>>>>>> On 1 November 2010 10:24, Marc Paré<marc at marcpare.com>   wrote:
+>>>>>>              
+>>>>>>> Le 2010-11-01 06:00, Philippe DIDIER a écrit :
+>>>>>>>                
+>>>>>> Using delta rpms would reduce the size of the updates, or has my lack
+>>>>>> of understanding of delta roms got in the way?
+>>>>>>              
+>>>>> Delta rpms, relative to the latest distro release, are long overdue.
+>>>>> (And not only in the Mandriva world.  Also for Mozilla, OpenOffice,
+>>>>> etc.)
+>>>>> Note that for much commercial software, updates are normally delta.
+>>>>> Such updates are often erroneously called patches.
+>>>>> This may be partly a limitation of rpm packages, or more the
+>>>>> programs  that install/update such packages.  If so, it should be a
+>>>>> priority to  correct this lack.
+>>>>>            
+>>>> The problem of delta rpm is the work need to generated alls delta and
+>>>> the space need on mirrors to host everything.
+>>>> We must provide delta for each version to the next one:
+>>>>
+>>>> - main foo-1
+>>>> - upd  foo-2 D: 1->2
+>>>>        foo-3 D: 2->3 and 1->3 ?
+>>>>        foo-4 D: 3->4 and 1->4, 2->4 ?
+>>>>
+>>>> etc...
+>>>> What if delta 1->4 is bigger than the package itself ? and for 2->4 ?
+>>>>          
+>>> As nanar points out delta rpm is a bad design
+>>>
+>>> a working concept would have been basing all deltas on a specific rpm
+>>> (i.e. the one in */release) and bundling entire files. in this case a
+>>> patch will grow at most as the original rpm, and you don't care about
+>>> keeping incremental diffs.
+>>>
+>>> L.
+>>>        
+>> Which is exactly what I was proposing.
+>> Delta by file relative to the official distro release.
+>>      
+> So to update from -1 to -3 I'll download around 300KB but to upgrade
+> from -2 to -3 I'll download the full rpm so maybe around 20MB (in the
+> case the rpm is 20MB) ?
+>    
+No no no no no !
+If from -1 to -3 is 300K, then upgrading from -2 to -3 would still be 300K.
+
+Of course, this raises the point that the names of the original files in 
+-1 will have to be retained after updates, as well as the names of files 
+replacing them, in order to make the additional updates.  (And remove 
+any interim updates subsequently replaced.)
+This could be facilitated by making the names of the replacement files 
+in delta updates the original file name + a suffix corresponding to the 
+delta update.
+
+Downloading the full rpm would only be need if one wanted to install a 
+package not yet installed.  And of course the latest delta update, if any.
+Of course, if full updates are retained, then one only downloads the 
+full update, as it will be a full rpm.
+
+> It's a proposal like others...
+>
+> I am not sure people having slow connections will enjoy this.
+>    
+They will, as long as the proposal is well understood.
+And adequately explained, of course :)
+
+- André
+