[olug] Fedora 23 -> Fedora 24 update roundup

[Lou Duchez]

I like to drop a line every time a new Fedora comes out and I update my 
servers, to help out the next guy who might be thinking of it.  This 
time, four out of five servers did fine, one server ran into terrifying 
problems but everything worked out okay in the end.

---

General update instructions

1) Make sure I'm up-to-date with my copy of Fedora (the old version).

dnf upgrade
reboot

2) Update to the new version of Fedora.

rpm --import 
/etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-[NEWVERSIONNUMBER]-$(uname -i)
dnf clean all
dnf --releasever=[NEWVERSIONNUMBER] --setopt=deltarpm=false 
--allowerasing distro-sync
/usr/sbin/grub2-install [BOOTDEVICE]
reboot

You can determine [BOOTDEVICE] by running:

df | grep "\/boot$"

And if it comes back with, say, "/dev/sdc1", the boot device is "/dev/sdc".

---

Easy!  That worked flawlessly on four out of five servers.

The terrifying part was, Grub2 didn't take for whatever reason on one of 
my servers, and so I couldn't boot it back up.  I am guessing I failed 
to do the grub2-install quite as well as I thought I had. To reinstall a 
functioning Grub2, I did the following:

1) Boot from the Fedora Live CD.

2) Hit Ctrl-Alt-F2 to go into terminal mode.

3) "cat /proc/partitions" to try to find my boot partition.

4) mkdir /tmp/bootpartition
     mount /dev/[whatever] /tmp/bootpartition
     /usr/sbin/grub2-install --boot-directory=/tmp/bootpartition 
/dev/[whatever]

5) Reboot / pray / drink heavily.  The combination of all three worked.

6) Try to install Grub2 again per the normal update instructions, just 
to make sure that Grub2 is consistent with what's on my hard drive 
rather than my Fedora Live CD.  I don't know if it makes a difference 
but it seems like a defensible step to take.