- It will allow us to quickly build environments from templates provided by Oracle and GOLD images we create.
- We will be building many environments to evaluate different software solutions. With Oracle VM we can keep the installations separate and when not in use they can be shut down.
- We can place our DEV servers into a single server pool. This provides us with load balancing and the ability for the vm's to run on any server in the pool. In the event of planned hardware maintenance we can also migrate vm's to other servers in the the pool without downtime.
- As a DBA it provides me with some extra freedoms. I can clone a VM to test patches, upgrades, etc and not disturb the developers.
- I'm sure there are more benefits.
Number 2 and 3 will help maximize resources and maybe even be able to run more environments than I could on bare metal.
I'll be honest, I am a skeptic when it comes to virtualization. There have been plenty of discussions on the Oracle-L and OAUG mailing lists with pros/cons and success stories. I believe virtualization makes perfect sense for certain situations such as training. I've been using it myself for the past couple of years to practice/learn things I otherwise couldn't. (Such as RAC.) Time will tell whether or not we will see any benefit from this in our environment. I'll be sure to post a follow up in a couple of months.
Installing Oracle VM was pretty easy but I did have a couple of issues. The VM Manager installed within minutes. Although, my first few attempts failed. I created a CD from the ISO images provided by Oracle but instead of walking down 5 flights of stairs to the server room (bad ankle), I took the 'lazy' approach and copied the CD to local disk on the server. The install proceeded without any errors but the VM Manager wouldn't start properly. On my way out of the building I mounted the CD in the server, reinstalled and it worked flawlessly. Not sure why it caused me problems because I have staged other Oracle products the same way without issue.
Oracle VM Server was a bit more difficult but I believe that is due to my hardware configuration. I am not sure why but when installing any flavor of linux (including the VM Server), the SAN drive is placed ahead of local disk in the boot order. Apparently the BIOS is responsible for providing the details of the correct drive order but everything looked fine. The controller servicing local disk was listed before the controller connected to the SAN and on top of that, it wasn't even configured to be bootable. So by default, the boot loader was being installed on the MBR for the SAN. After a reboot I would receive GRUB errors.
With a full Linux distribution such as RedHat or Oracle Enterprise Linux you are provided with some advanced boot loader configuration options, one of them being to change the drive order. By manually placing the local disk ahead of the SAN, I am now provided with the option to install the boot loader on the MBR of the local disk. I can now install Linux and boot with no issues.
Oracle VM Server however, doesn't provide you with any advanced boot loader configuration options. So I had no choice but to place my SAN controller ahead of the local controller in the boot order and allow it to be bootable. However, when I rebooted I was greeted with "Error 21: Selected disk does not exist". I examined the grub config and noticed that it was trying to boot from "root (hd1,0)". hd1 should be corresponding to my local disk since it was placed second in the boot order and this is where I placed the /boot partition (along with the rest of the VM server install). I wanted to reserve the SAN drive for the /OVS directory, which is where all of the VM's are stored and also the bulk of my disk space.
For some reason tho, local disk is hd0. I edited the grub config to boot from "root (hd0,0)", restarted and it worked flawlessly. I'll admit, i'm not a server admin in a professional sense. I've been using linux since around ~93 (Slackware version 1), so I can figure things out but i've never supported it in a corporate environment with server class hardware before. I wouldn't be surprised if there is some hardware/BIOS config issues at play here.
Now that its installed, the fun begins!