what has 'yum update' done?

[lee]

Matthew Miller <mattdm at fedoraproject.org> writes:

> On Sun, Jul 14, 2013 at 12:51:05AM +0200, lee wrote:
>> > You could try using yum-cron.
>> Automatic updates?  I'd rather not do that since it sometimes seems
>> advisable to reboot after an update.
>
> It's often advisable, but usually only because the updates may not take
> effect on already-loaded code and not all updates can restart all relevant
> services. So, applying updates and not restarting should be no worse than
> not restarting at all.

It depends --- I would recommend to restart everything that has been
affected by updates because old code running might conflict with new
code loaded later (an updated library which is loaded by something that
wasn't restarted, for example).  This can lead to problems, like an
application or an X session crashing.

Not everything can be restarted even manually.  When I have to close my
X session, I can as well reboot.  When I get a new kernel, why not just
reboot?  If I'm using software raid and get a new kernel and/or new
mdtools, it might be a good idea to reboot, either to take advantage of
whatever is new or to make sure that the mdtools in use are compatible
with the running kernel.

How would automatic updates help me?  Should I even update frequently
when everything is working fine?  Why not just let it run as is until I
feel I want to update?

>> > Or, if you're interested in hacking a little
>> > bit, you could adapt
>> > ftp://linst.bu.edu/updates/monde/SRPMS/bulinux-autoupdate-1.1.8-bu50.7.src.rpm
>> > which I made for Boston University Linux back in the day. It would be kind
>> > of cool to see it made more generic (and possibly integrated with yum-cron).
>> > It's designed to give a sysadmin-friendly e-mail report of all packages
>> > updates.
>> It's not simply about knowing which packages have been or are to be
>> updated --- that I can see when running 'yum update'.  It's about
>> information what has actually changed when a package was updated.
>
> The problem here is that we have an overwhelming number of updates in
> Fedora. It would be very time-consuming to read them all.

You would need to read only the ones that concern you.

> If you're interested or know you need this level of detail on your
> system, it's best to become familiar with the package names and check
> manually when you see an important package being updated.

Isn't that much more time consuming, and doesn't it leave more room for
mistakes than looking at a number of emails?

With the emails, you might even become aware of important changes of
packages you otherwise wouldn't have considered as important.

If there was an option to disable or to enable the mailing for
particular packages, you could reduce the number of mails by enabling
them for only those packages you consider as important.

>> The package maintainer knows what changed, and it doesn't hurt to add a
>> short note like this when they're making a new version of a package.  In
>> case there was a bigger change, the email could always suggest what
>> documentation to look at.
>
> Well, going to back to my first post in the thread, the package maintainer
> doesn't always know what changes are going to affect users. They should have
> a general idea, but software is complicated. 

When the maintainers inform the users about changes, the users can
decide for themselves whether the changes affect them or not.

>> Why not make it one of the great features of Fedora? 
>
> This update information _is_ produced. It's just not always done as well as
> it could be, and the tools don't make it available in the way you'd like
> right now.

If there was a mechanism available that allows package maintainers to
easily put a note into their packages which is then mailed after
installing the packages, perhaps they would just use it.

They might not use it every time, some might not use it at all.  Some
might only use it when they think there was an important change users
should be informed about.

It could help to give users better information.

If you were maintaining a package and if you could simply write a
sentence like "The configuration has changed, please check yours." at a
place you probably look at anyway when making a new package, wouldn't
you go ahead and write that sentence so it can be mailed to the users
using your package?

>> Then take it to the next step and make systemd send mails in case a
>> service couldn't be started or has issues, and optionally have it send a
>> mail after booting has completed with a list of services that were
>> started.
>
> Generally, I don't think "more things generating e-mail" is the future of
> systems administration. :)

What do you think it is? :)


-- 
Fedora release 19 (Schrödinger’s Cat)