ERROR with rpm_check_debug vs depsolve:
kernel-headers is needed by glibc-headers-2.12-1.166.el6_7.3.x86_64
kernel-headers >= 2.2.1 is needed by glibc-headers-2.12-1.166.el6_7.3.x86_64
kernel-uek is needed by oracle-rdbms-server-11gR2-preinstall-1.0-12.el6.x86_64
kernel-uek is needed by oracle-rdbms-server-12cR1-preinstall-1.0-14.el6.x86_64
** Found 4 pre-existing rpmdb problem(s), 'yum check' output follows:
glibc-headers-2.12-1.107.el6_4.4.x86_64 has missing requires of kernel-headers
glibc-headers-2.12-1.107.el6_4.4.x86_64 has missing requires of kernel-headers >= ('0', '2.2.1', None)
oracle-rdbms-server-11gR2-preinstall-1.0-7.el6.x86_64 has missing requires of kernel-uek
oracle-rdbms-server-12cR1-preinstall-1.0-8.el6.x86_64 has missing requires of kernel-uek
Your transaction was saved, rerun it with: yum load-transaction /tmp/yum_save_tx-2015-11-17-08-39DucKzd.yumtx
Very strange. I have never needed to install kernel headers to complete this task before. So, I install kernel headers and still it insists on installing the UEK kernel - so I do. Now it allows me to fully patch the system.
Installing : kernel-uek-firmware2.6.32-400.37.12.el6uek.noarch
Installing : kernel-uek-2.6.32-400.37.12.el6uek.x86_64
Installing : kernel-headers-2.6.32-573.8.1.el6.x86_64
I reboot and now my Azure appears to hang. There is nothing I can do - with no console to see what's going on or choose a different kernel or single user mode. I'm stuck. Of course, there is always the procedure of detaching the drive, adding it to a rescue VM, editing, chroot'ing, re-running grub - yeah, fun.
I suspect it is trying unsuccessfully to boot the Unbreakable Linux Kernel (um, yeah, I've seen that break things before). So, I scrap this new install and start again. This time, taking it slow. I remove the item requiring UEK:
yum remove oracle-rdbms-server-11gR2-preinstall oracle-rdbms-server-12cR1-preinstall
I do not need to run Oracle on this system (luckily - because this is really handy if you do) so now I can just install kernel-headers and re-run yum upgrade. I do this - then reboot and it works. (Strangely enough - I try Oracle Linux 7 and do not have this issue. I need to review and see why [updated post later].)
Meanwhile, I run across this blog post from last month stating "UEK2 is not supported on Hyper-V and Azure as it does not include the required drivers". yup - found that out the hard way.
I also noticed my favorite volume manager LVM is not installed by default. I needed to add more disk space and would probably need to grow the data area in the future so I add a VG (volume group) for data and create a PV and LV (Physical and Logical Volume) for the data and logging areas. Seem to work ok. But the above blog post (from last month) says: "it is recommended that you use standard partitions rather than LVM". It complains mainly of issues with LVM name conflicts with cloned VMs. I really think that was more of an issue with RHEL 5 (they named everything the same). Anyway, my LVM group is, so far, unique, so I'm not worried (but I'll have to remember this).
That's all from me. The documentation above covers a lot of Oracle Linux 6 issues and work-around. Be sure to click on it.