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). 

When your VM gets stuck in suspended mode in Red Hat KVM...

I needed to re-do my network interfaces in KVM - make more bridged Ethernet connection for the VMs to use.  I totally forgot that I had a guest VM running as I began my reboot.  "Suspending SSB2" it says as I panic suddenly realizing what I had done.  It's ok - I've done this before I quickly remember.  It does a great job of automatically suspending and resuming UNLESS YOU JUST HAPPEN TO CHOSE THAT REBOOT TO SCREW UP THE NETWORK CONFIGURATION.

So, it reboots and networking is goofed.  I quickly see what I did, fix and reboot again.  This time it's ok but the SSB2 VM does not start.  I try to start it manually and get the message:

libvirtError: error creating macvtap type of interface: Device or resource busy

Whatever that means.  (It actually means I tried to un-suspend but couldn't talk to the iSCSI network so we're leaving it in limbo).  I google and google and find a lot of folks in the same boat.  They came up with some very iffy and convoluted solutions involving editing multiple XML files, etc.  I follow the threads to the bottom of each.  None of them seem quite right.

New to KVM, I try clonging the non-startable SSB2 and succeed.  It boots and works (requires a lot of network changes, but oh well).

Still not satisfied I see mention of "/var/lib/libvirt/qemu/save/rhel.save"  (it's ssb2.save in my case).  Again some very complicated procedures involving editing multiple XML files, etc. with no guaranteed results by the author.

Since I have a working clone, I figure "What the heck!  I'll just delete "/var/lib/libvirt/qemu/save/ssb2.save" and try starting.  It worked!  -Except for one snag - I already had an exact doppleganger running.  It locked up my virt-manager and the server hard.  After, rebooting all was well.

This worked for me.  On a TEST system.  Use at your own risk.