The Joy of Modern Computing

1. Solaris Zones & Containers
2. Oracle VirtualBox
3. Xen 
4. VMware
5. KVM 
6. Heroku
7. Hyper-V 
8. Citrix XenServer 
9. Oracle VM Manager (OVM) 
10. Amazon Web Services (AWS) 
11. Microsoft Azure Cloud Services

These are a few of my favorite virtualization platforms that I've been using since 2006. I love virtualization!  I work mainly out of a virtualized desktop running ssh into virtualized systems.   Lately, I've been working a lot with Microsoft Azure Cloud Services.

It's funny how this is perceived by some people unfamiliar with it.  Today in a meeting, some people thought that moving systems to the "cloud" would cause a loss of IT positions.  I never thought so.  My least favorite part of the job is the part that takes .001% of your time - mounting the physical hardware in a rack and wiring it.  If that goes away, I will not miss it at all.

I love that I can clone, copy and snapshot VMs.  Using physical hardware now seems to me like working without a net. I would not want to go back.  Even better is having the services in the cloud.  No messy wires, no failing hard drives (I have an open ticket for one now).  Even backups are a breeze.

I have a 32 bit Windows 7 desktop VM that I migrated from a PC running CentOS 5 under Xen to a PC running Red Hat Linux 6 running KVM (that was a tough migration - but it worked!) and then I moved it again to a PC running Oracle Linux 7 under KVM (much easier move).  So, my Windows 7 has been with me through 3 PCs.  All of my stuff is there - all my files and software.  Virtualized PC's are really cool!

I also run additional VMs on my PC.  If a new distro comes out and I want to see what it looks like - I just load it from the ISO!  I don't have to have spare hardware.  It's great!  I have been running my desktop like this about 6 years and can't imagine doing it any other way.  (I started virtualizing my servers almost 10 years ago).

Lately, as I have built about a dozen various VMs in Azure.  I've been testing the cloning of VMs & filesystems and securing endpoints. (It took some time to figure out how to reserve static addresses.)

Now, I love Linux and my technology passion is learning pretty much anything OpenSource - BUT, even though I could do quite a bit with the cross platform kit for Azure under Linux - most of the work was easier in Powershell.  No problem - because I really like Powershell - BUT, my 32 bit Windows 7 system didn't seem to want to finish the install and hung twice.  I figured it was because it was 32 bit.  Again, thanks to virtualization - No problem - I just loaded up 64 bit Windows 10.  (I tried to like Windows 8 and 8.1 but eventually gave up. Skipping that one.)  Windows 10 is a nice mix and seems more intuitive then its predecessor and ran the Azure Powershell environment which made cloning much easier.

The cool thing is, I can still run my old Windows 7 for as long as it gets patches (and then I could just remove the network and keep it for nostalgia) BUT I also get to run Windows 10 and use the Azure Powershell features I need.

Anyway, Linux and KVM gives you a lot of possibilities and it's free (your VMs, may not be). 

Azure and Oracle Linux 6

Typical of my luck - the VERY FIRST Azure VM I install is the Oracle Linux 6.4.  Of course, the first thing I do after a new install is "yum upgrade".  For the first time ever, I get a weird error and cannot complete this:

...
Running rpm_check_debug
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.