Tian Zhiying wrote:

I'm running OpenLDAP 2.3.43 in CentOS 5.8 64bit,

Both are ancient.

now I want to update OpenLDAP from 2.3.43 to latest.

Very good plan.

How can I do it ?

If no way update from 2.3.43 to latest, how can I migration data of 2.3.43 to new OpenLDAP?

I'd strongly recommend *not* to do an in-place upgrade.

You should rather

1. Set up a test system with a recent release (you get OS upgrade as a bonus).

2. Export your current DB to LDIF with slapcat.

3. Try to use your config on the test system, import LDIF export with slapadd and conduct all necessary tests. Note that ACL processing slightly changed from 2.3 to 2.4.

4. Build up new production system and test.

5. Switch LDAP applications to use new system.

6. Stop old system(s) and wait which LDAP client applications do not work any longer. ;-)

Ciao, Michael.