Thanks Aki for the answer.

I did some tests and found a solution. I write down my experience It could be useful to someone.

First I putted  "passwd-file" passdb (only)  before "pam" passdb, as Aki suggested, but "illegal seek error" persisted.

Then I putted both "passwd-file" passdb and "static" userdb before "pam" passdb and "passwd" userdb (used for local user), but that generated a strange behavior because "static" driver overrides info also for local user.

Finally I putted both "passwd-file" passdb and "passwd-file" userdb before "pam" and "passwd" and that works without errors.

My working dovecot config:

host-prompt# dovecot -n # 2.1.7: /etc/dovecot/dovecot.conf # OS: Linux 3.2.0-5-686-pae i686 Debian 7.11 auth_mechanisms = plain login auth_username_format = %Ln listen = * log_timestamp = "%Y-%m-%d %H:%M:%S " login_greeting = Server ready. mail_full_filesystem_access = yes mail_location = mbox:~/:INBOX=/var/mail/%u:INDEX=/var/index/%u mail_privileged_group = mail passdb { args = scheme=MD5-CRYPT username_format=%n /etc/dovecot/users driver = passwd-file } passdb { driver = pam } protocols = " imap" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } user = root } service imap-login { inet_listener imap { port = 0 } } ssl_cert = </etc/ssl/certs/chained-cert-9599-ml.mat.unical.it.pem ssl_key = </etc/ssl/private/csrkey-ml.mat.unical.it.pem userdb { args = username_format=%n /etc/dovecot/users default_fields = mail=maildir:/var/vmail/%d/%n/Maildir/ driver = passwd-file override_fields = uid=vmail gid=vmail home=/var/vmail/%d/%n } userdb { driver = passwd } verbose_proctitle = yes

host-prompt# cat /etc/dovecot/users claudio.panetta:{MD5-CRYPT}$1$abcdefghijklmnopqrst:5000:5000::/var/vmail:: ciccio.pasticcio:{MD5-CRYPT}$1$abcdefghijklmnopqrst:5000:5000::/var/vmail::

At first I preferred (making a mistake) static driver versus passwd-file to avoid writing uid,gid,home for each user, but in the end, with passwd-file and override_fields i got the desired scenario.

Regards, Claudio

Il 30/03/18 14:27, Aki Tuomi ha scritto:

...

On 30 March 2018 at 15:11 panetta <panetta@mat.unical.it> wrote:

Hi,

I recently configured dovecot to manage auth for both local and virtual user. When i login as a virtual user (claudio.panetta) I get the following message:

dovecot: auth: Error: passwd(claudio.panetta,160.97.62.1,<WLjlnZ9oRACgYT4B>): getpwnam() failed: Illegal seek

but login is ok and sending/receiving email is ok, how can, if possible, I suppress this error message?

In the following my dovecot config:

host-prompt# dovecot -n # 2.1.7: /etc/dovecot/dovecot.conf # OS: Linux 3.2.0-5-686-pae i686 Debian 7.11 auth_mechanisms = plain login auth_username_format = %Ln listen = * log_timestamp = "%Y-%m-%d %H:%M:%S " login_greeting = Server ready. mail_full_filesystem_access = yes mail_location = mbox:~/:INBOX=/var/mail/%u:INDEX=/var/index/%u mail_privileged_group = mail passdb { driver = pam } passdb { args = scheme=MD5-CRYPT username_format=%n /etc/dovecot/users driver = passwd-file } protocols = " imap" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } user = root } service imap-login { inet_listener imap { port = 0 } } ssl_cert = </etc/ssl/certs/chained-cert-9599-ml.mat.unical.it.pem ssl_key = </etc/ssl/private/csrkey-ml.mat.unical.it.pem userdb { driver = passwd } userdb { args = username_format=%n /etc/dovecot/users uid=vmail gid=vmail home=/var/vmail/%d/%n mail=maildir:/var/vmail/%d/%n/Maildir driver = static } verbose_proctitle = yes

host-prompt# cat /etc/dovecot/users claudio.panetta:{MD5-CRYPT}$1$abcdefghijklmnopqrst ciccio.pasticcio:{MD5-CRYPT}$1$abcdefghijklmnopqrst

Regards, Claudio

Hi! Put the file based passdb before the pam one. Also not sure what you are trying to do with the static userdb. It looks like you wanted to use passwd-file?

Aki