Re: Modifying existing schema definition without reimporting data ?

[Quanah Gibson-Mount <quanah@stanford.edu>]

--On Friday, January 05, 2007 1:43 PM +0100 "Heinzmann, Robert" 
<Heinzmann@cc-dresden.de> wrote:

> Hello,
>
> is it possible to change Schema definitions on openldap servers without
> recreating the backend ?
>
> Background: We have a ldap server (or multiple replicated LDAP servers)
> and have a certain attribute in the schema defitnion that is currently
> defined as "single value". It's the MAC address for clients used for
> X802.1 auth. The attribute is part oif the user object used for logins.
> Now it's possible, that users have multiple MAC addresses. We want to
> add multiple MAC addresses to that list, so we must chnage the attribute
> type from single to multiple values (sorry, I don't know the exact name
> of the defintion statement).
>
> Would this be possible by doing the following:
>
> stop ldap slave server
> change schema defintion for MAC address attribute from single to
> multivalue
> Start ldap slave again
>
> stop ldap master
> change schema defintion for MAC address attribute from single to
> multivalue
> Start ldap master

That looks fine.

> Is changing the schema definion generally possible for changes other
> then singlevalue->multivalue - e.g. add another attribute or modify
> other things ?

It depends on what the change is.  Adding new attributes you can generally 
do, or deleting them, if they are not required by an objectClass.  Changing 
data types, and the objectClass type (aux vs structural), etc, isn't 
generally going to fly.

I'll note that in 2.4, you will be able to change the schema on the fly 
(i.e., no server restarts) if you use back-config.  There is some limited 
support for this already in 2.3.

--Quanah


--
Quanah Gibson-Mount
Principal Software Developer
ITS/Shared Application Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html