The FHS /usr song (was: Core packages are using %config for files being installed under /usr)

[Nicolas Mailhot]

Le Lun 5 mars 2007 12:39, Ralf Corsepius a écrit :
> On Mon, 2007-03-05 at 12:11 +0100, Axel Thimm wrote:
>> On Sun, Mar 04, 2007 at 10:47:18PM -0500, Matthias Clasen wrote:
>> > How exactly do you propose packages should install anything under /usr
>> > if its readonlyness is so sacrosanct ? Does it at least occur to you
>> > that it cannot be readonly at install time ?
>>
>> Please don't be so literate, we already looped twice around the world
>> explaining this. If you read it letter by letter and ignore FHS'
>> intentions you may indeed logically conclude that /usr would be an
>> empty filesystem, but try reading the full context.
>>
>> The bottom line is: Don't %config/%config(noreplace) files under /usr.
>
> 1. When will you finally understand that rpm's %config has nothing to do
> with configurating a system. %config only specifies rpm's behavior upon
> handling of backups upon install.

%config marks files that rpm needs to "preserve" because they can be
modified legitimately outside of its control. One of the main FHS
arguments for making /usr ro is it doesn't need to be backup-ed. When you
use %config on a /usr file you're explicitely asking rpm to do something
the FHS told you should not be necessary on a well-designed system.

Not having to hunt modified files everywhere on the filesystem and knowing
/usr can be recreated from the install media is a major sysadmin boon.

-- 
Nicolas Mailhot