[YLUG] fedora 10 login

[mike cloaked]

On Sun, Feb 1, 2009 at 1:29 AM, Harry Mills <mail at hjmills.co.uk> wrote:

> If, as it sounds, you have upgraded directly from Fedora 7 to Fedora 10
> without going via Fedora 8 or 9 then you should really be expecting
> problems. The releases are often well tested to ensure they are clean to
> upgrade from the previous version but they cannot check every single
> previous release.
>
> It also sounds as if you have been running the same root partition with
> the same setup since a Red Hat 4 installation. I would be very tempted
> to do a full back up of any important data, upgrade to a larger hard

I wonder what size the root partition is in his case?  I would not use
a partition for root of less than 10GB, and these days I allocate 15GB
so that large updates will not overfill the partition.

Some years ago I remember running a yum update and monitored the disk
space usage during the process - initially of course all the update
rpms come in to /var/cache/yum - then then the system needs temporary
space in /tmp whilst it processes the updates so the disk usage
increases to a peak, and eventually reduces again as it cleans up
towards the time that the update process completes, leaving only the
additional space used by the update rpms.

If there has been an install quite some time after initial release
then the space occupied by update rpms can be over 1GB and the
temporary additional space can be as much again or more. You can of
course update partly and then remove the update files (yum clean all)
and then update other stuff if you are short of space but it is a lot
easier to have sufficient space to start with.  Also you need to check
the file /etc/yum.conf - the parameter keepcache =1 will hold onto the
update rpms whereas keepcache=0 will delete update rpms after yum
completes.

If the root partition is only just a little bigger than the installed
system (depending on the packages included in the install) then
updating can be problematic for sure and /tmp and /var/tmp need to
grow as necessary depending on which applications are running. Hence
my suggestion to have around 15GB available for / - I have never found
a need to have any more than /opt or /home as additional partitions,
and indeed one can make a /home/opt or /opt/home and bind mount to the
normal locations (/opt or /home as necessary) in the system.
Occasionally for an encrypted system there is a need for a separate
non-encrypted /boot partition.  But there is certainly no need for
separate /tmp or /var/tmp partitions and you may as well just make a
larger root partition in the first place. This also means that when
upgrading to a new version you only need to reformat the / partition.
Leaving old /tmp separate partitions lying around with stuff in them
may also lead to problems. All user areas and other local stuff is
then kept in the /opt or /home partitions provided the installer is
told not to touch these non-root partitions but only to mount them
after the install is complete. That way upgrading the system is
relatively painless, and configuring the system after the clean
install to include the previous user areas is not too long a process
but you are then comforted by the knowledge that you have a clean root
area. I think in the OP's case he is using LVM - but I believe you
need to be sure you are using LVMs correctly to prevent problems.

There was a comment in a previous post on selinux - and indeed in F10
selinux is enabled during install without an option to disable it.
This is fine but if you are linking in files on non-root partitions
after the install then you certainly need to spend some time reading
about how selinux works and how to use it to fix avc denials. Check
the Fedora wiki for a complete guide to using selinux.  I recently
updated a whole series of machines from f8 to f10 and kept the old
user areas - you have to relabel the files using restorecon initially
and then change contexts for any files for applications that are not
covered by the standard targeted policy, or for applications that you
installed outside of Fedora eg from tarballs.  You need to know about
chcon and semanage at the minimum. If you charge in with both feet and
without knowledge things will likely not go well!  Reading the selinux
guide is the first step. Either way files from a previous system where
selinux was disabled will have no security context in F10 - and you
cannot run an selinux system if files have no context!  Of course if
you wish you can set selinux to disabled after the install but the
better way forward is to set it permissive (so it won't act on
denials) but you then have time to fix the problems before eventually
setting back to enforcing. If you set SElinux to disabled - then going
back to enforcing later is not straightforward.

I hope this helps.


-- 
mike