Hi Rob. 
Yes. I am following the link you sent. So now I can understand they need to create the new Kerberos but given the command I should have seen all the users in the new freeipa server... which are not there. 
Maybe I put a wrong command? (below)

ipa migrate-ds --bind-dn="cn=Directory Manager" --user-container=cn=users,cn=accounts --group-overwrite-gid --group-container=cn=groups,cn=accounts --group-objectclass=posixgroup --user-ignore-attribute={krbPrincipalName,krbextradata,krblastfailedauth,krblastpwdchange,krblastsuccessfulauth,krbloginfailedcount,krbpasswordexpiration,krbticketflags,krbpwdpolicyreference,mepManagedEntry} --user-ignore-objectclass=mepOriginEntry --with-compat ldap://192.168.20.177:389

Password:
-----------
migrate-ds:
-----------
Migrated:
  group: admins, editors
Failed user:
  admin: This entry already exists
Failed group:
----------
Passwords have been migrated in pre-hashed format.
IPA is unable to generate Kerberos keys unless provided
with clear text passwords. All migrated users need to
can use their Kerberos accounts.





On Tue, Aug 14, 2018 at 5:01 PM Rob Crittenden <rcritten@redhat.com> wrote:
Alfredo De Luca via FreeIPA-users wrote:
> Hi Florence. Thanks again. I understand about the password hash... but
> does it mean all the users need to do that before migration? or after? 
>
> Cause in the new ipa server can 't see any of the users/groups. 

Then I assume the migration failed?

I believe there is a chapter in the RHEL docs on migration and it is
also mentioned at https://www.freeipa.org/page/Howto/Migration

Users will need to re-authenticate themselves post-migration in order to
set their Kerberos credentials.

rob


--
Alfredo