On 16/11/2012 12:11 PM, Dmitri Pal wrote:
On 11/16/2012 10:59 AM, Qing Chang wrote:
just migrated all my user from OpenLDAP and MIT Kerberos to IPA.

Out of more than 400 users, there are around 10 that have problem
accessing Samba or Dovecot IMAP or ssh.

They never have problem login to ipa/ipa/ui/login.html.

For Dovecot IMAP following error is generated:
Nov 16 10:15:03 dovecot2 auth: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=uesrid rhost=IP user=userid Nov 16 10:15:03 dovecot2 auth: pam_sss(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=userid rhost=IP user=useris
Nov 16 10:15:03 dovecot2 auth: pam_sss(dovecot:auth): received for user userid: 
4 (System error)

Hello Qing

There are several things to do:
1) Compare entries of the users that login with no problems and users that have problems. There might be some attributes different (absent/present). That might give a hint of what might be wrong. We have seen some issues in this area related to Samba. 2) Can you please enable the higher debug_level in SSSD and provide the SSSD logs + sssd.conf that would help to see what is going on with the user that is failing. 3) Also if you can describe your environment of how all the parts work together and what are the workflows in which you see the problem/issue. I am personally not familiar with Dovecot in details so I assume that Dovecot is configured to use PAM for the authentication and the snippet above is from that authentication. Is this the correct assumption?



appreciate your prompt response. I having being on this thing for past day and 
a half,
I think I now understand the issues and found fix/workaround for them.

1, Samba + IPA: when this attribute sambaPwdLastSet is set to 0, a samba mapping
    request will cause samba to CLEAR sambaLMPassword and sambaNTPassword
    attributes, yes, not set password to something, but the attributes are 
wiped out.
    This may only apply to my situation because I HAVE to use samba 3.0.23d, a
    ancient version!! Originally when I migrated users from OpenLDAP, 
    has a none zero value for every account. As users migrated their password 
    the value was not touch. But, if someone's password has to be reset (too 
short, forgotten)
    by us admin user using the UI, sambaPwdLastSet is set to 0. This explains 
why the
    problem is not wide spread.
    Fix/workaround: change sambaPwdLastSet to a sensible value after a password
    reset by admin.
    Question: is this a designed behavior for IPA? Or does migrate-mode or not 
make difference?

2, Dovecot + IPA: it is not an IPA issue but sss cache timeout issue, I read 
it's 90 min?
    When a user changes his/her password, the cache usually is not updated, 
    problem checking IMAP email with new password.
    \rm /var/lib/sss/db/cache_sri.utoronto.ca.ldb
    service sssd restart
    This is really heavy handed, but I can not find the sss_cache utility any 
where for
    RHEL 6.3!
    Question: is there a way to shorten the timeout period? Where can I find

I have great confidence in IPA now, big part of it is because of this list!!

Many thanks,


For Samba, it appears that a mapping request never gets to Samba server because
nothing is logged for a problematic user ID although I have turned on excessive 

What is really frustrating  is that there is no pattern to be found, even my 
Sysadmin's ID is also in trouble.

Also, in his case, he has no problem with Dovecot. For another user ID Samba 
but not Dovecot. It looks to me there might be some problem with sssd on the
different servers?

BTW, for at least one user, creating a brand new account for samba did not work 
while the trick worked for another user:-(.

Please shed some light on this. I don't mind opening a case with RedHat support
if necessary.

Red Hat Enterprise Linux Server release 6.3 (Santiago)
ipa-server.x86_64 2.2.0-16.el6            @rhel-x86_64-server-6
sssd.x86_64                      1.8.0-32.el6 @rhel-x86_64-server-6
sssd-client.x86_64               1.8.0-32.el6 @rhel-x86_64-server-6


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Thank you,
Dmitri Pal

Sr. Engineering Manager for IdM portfolio
Red Hat Inc.

Looking to carve out IT costs?

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