Answering my own question, I figured out that the output was due to 
something in the "psacct" file in /etc/logrotate.d/, and more 
specifically due to systemctl.  (The reason my newer systems didn't give 
the same output was that the psacct service hadn't been enabled on those 
systems yet, even though it was installed.)

Here's the simple fix, for now (until someone managing systemd figures 
out what "--quiet" should really mean).

Gilbert

--- /etc/logrotate.d/psacct.EL7.rpmsave 2016-11-03 22:12:33.000000000 -0500
+++ /etc/logrotate.d/psacct     2017-04-27 10:37:13.127737439 -0500
@@ -8,7 +8,7 @@
      rotate 31
      create 0600 root root
      postrotate
-       if /usr/bin/systemctl --quiet is-active psacct.service ; then
+       if /usr/bin/systemctl --quiet is-active psacct.service 
2>/dev/null ; then
             /usr/sbin/accton /var/account/pacct | /usr/bin/grep -v 
"Turning on process accounting, file set to '/var/account/pacct'." | 
/usr/bin/cat
         fi
      endscript

On 25/04/2017 10:47 AM, Gilbert E. Detillieux wrote:
> Since installing some updates (including a new kernel) and rebooting
> back on Feb 23, anacron has been e-mailing me the following output daily
> on all my SL7.3 systems:
>
> -------------------------------------------------------------------------
> /etc/cron.daily/logrotate:
>
> Got unexpected auxiliary data with level=1 and type=2
> Sent message type=method_call sender=n/a
> destination=org.freedesktop.systemd1 object=/org/freedesktop/systemd1
> interface=org.freedesktop.systemd1.Manager member=GetUnit cookie=1
> reply_cookie=0 error=n/a
> Got unexpected auxiliary data with level=1 and type=2
> Got unexpected auxiliary data with level=1 and type=2
> Sent message type=method_call sender=n/a
> destination=org.freedesktop.systemd1
> object=/org/freedesktop/systemd1/unit/psacct_2eservice
> interface=org.freedesktop.DBus.Properties member=Get cookie=2
> reply_cookie=0 error=n/a
> Got unexpected auxiliary data with level=1 and type=2
> Got unexpected auxiliary data with level=1 and type=2
> -------------------------------------------------------------------------
>
> Here's the list of update packages that were installed on the date in
> question:
>
> Feb 23 15:27:08 Updated: kernel-tools-libs-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:09 Updated: kernel-tools-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:21 Installed: kernel-devel-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:22 Updated: python-perf-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:24 Updated: kernel-headers-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:25 Updated: perf-3.10.0-514.6.2.el7.x86_64
> Feb 23 15:27:35 Updated: firefox-45.7.0-2.el7_3.x86_64
> Feb 23 15:27:47 Installed: kernel-3.10.0-514.6.2.el7.x86_64
>
> I doubt firefox or the perf packages are relevant, so I'm thinking it
> may have to do with the new kernel that was installed and booted then.
> Subsequent kernel updates haven't change the behaviour, though.
>
> Curiously, on a new SL7.3 system installed since then, with exactly the
> same kernel and set of logrotate config files, I don't see those errors.
>  Also, if I disable execute permission on /etc/cron.daily/logrotate on
> one of the affected systems, and run it manually from the command line
> the next day (instead of anacron running it), I don't see those error
> messages.
>
> This one has me stumped.  I'm not even sure exactly what part of
> logrotate is generating those errors, and it's hard to test it out since
> the errors only happen when running via anacron.
>
> Any ideas as to where I should look?
>
> Gilbert

-- 
Gilbert E. Detillieux		E-mail:	<[log in to unmask]>
Dept. of Computer Science	Web:	http://www.cs.umanitoba.ca/~gedetil/
University of Manitoba		Phone:	(204)474-8161
Winnipeg MB CANADA  R3T 2N2	Fax:	(204)474-7609