[CentOS] Understanding yum automatic upgrades

Wed Apr 6 01:38:29 UTC 2011
Brian Mathis <brian.mathis+centos at betteradmin.com>

On Tue, Apr 5, 2011 at 7:40 PM, email builder <emailbuilder88 at yahoo.com> wrote:
>> >> Sorry if this is somewhat naive, but I'm a little confused   as to what the
>> >> criteria is for that which will get upgraded  automatically by  yum and
> what
>> >> will not.
>> >>
>> >> I  see in our logwatch messages from  time to time that yum upgraded
>> >> a  bunch of stuff, but I also notice that yum  will not upgrade other
>> >>  packages at all (easy example is clamav, but there  are  others).
>> >>
>> >>  Can someone explain or point me to where I can  read  about the
> distinction
>> >> between what is and is not subjected to  automatic  upgrade?
>> >
>> > More info: yum-updatesd is running and I do  not have yum-cron.
>  yum-updatesd
>> > does a fine job from what I can tell,  but I still cannot understand what
>> > criteria it applies to know which  packages get upgraded and which do not.
>> (?)
>> >
>> > The yum-updatesd  configuration file is ultra-simple, so that doesn't seem to
>>be
>> > where the  update choice/distinction is being made.
>> >
>> > There seem to be people  posting in various places that they prefer to use
>> > yum-cron, but I have  no problems with yum-updatesd and I suspect yum-cron
>> > wouldn't  address/answer my question anyway.
>> >
>> > Help?
>>
>> Yum-updatesd  does not automatically install packages (unless you
>> configure it to), it only  notifies you of ones that need updating.  If
>> no one is manually doing  it, and you don't have "do_update = yes" in
>> /etc/yum/yum-updatesd.conf, then  you have installed something else
>> that is performing the updates  automatically.
>
> It does look like updates are happening, but it's not clear to me by whom.
> do_update is set to "no", but notification is by "dbus", so I assumed that
> "dbus" is notifying another process to do the actual updates.  Is there a way I
> can track that down?
>
>> Are you sure the updates are actually getting installed,  and it's not
>> just noise in the log from yum-updatesd?
>
> Well, if I can take it at its word, updates *are* happening.  Here is a snippet
> I clipped out of a logwatch a few months ago:
>
>  --------------------- yum Begin ------------------------
>
>
>  Packages Updated:
>    php-dba - 5.1.6-27.el5_5.3.i386
>    php - 5.1.6-27.el5_5.3.i386
>    php-devel - 5.1.6-27.el5_5.3.i386
>    php-cli - 5.1.6-27.el5_5.3.i386
>    php-common - 5.1.6-27.el5_5.3.i386
>    php-gd - 5.1.6-27.el5_5.3.i386
>    php-pdo - 5.1.6-27.el5_5.3.i386
>    php-mysql - 5.1.6-27.el5_5.3.i386
>
>  ---------------------- yum End -------------------------
>
>> P.S. The yum log doesn't have the year in the timestamp, and  if it's
>> not active it might not get rotated by logrotate.  This can  cause
>> false messages sent from logwatch about packages that were  installed
>> last  year.
>
> Hmm, is there a known fix for this?


Rotate the log file yourself once a year.  You can check if you are
seeing this bug by looking at the /var/log/yum.log last modified time.
 If it was yesterday, then I suppose the packages were installed.

As far as your other questions, how does it determine what packages to
update, I think you will find it's not actually doing any updating.  I
have not used yum-updatesd to auto-update packages myself, but I would
think it would automatically install any updated package.


// Brian Mathis