Over the last few days I’ve been installing a few different instances of Oracle into VirtualBox machines.

To ease the OS install headache I made a CentOS 5.2 guest with all the Oracle kernel optimisations and filesystem layouts as well as the required packages (such as the legacy C++ libraries). I then cloned that twice – once for Oracle10gR2 and once for Oracle11iR1; using the instructions here; which are essentiallty: clone the VDI file, register a new VM, change the UUID and mac address and attach the new disk.

It works well actually, although in typical VirtualBox fashion, requires a fair bit of manual hacking around instead of just copying a directory and clicking a button like with VMWare.

Oracle install instructions were from here for 11g and here for 10g

So then I tried to install Oracle 9iR2, well that was a different matter altogether. I had to go back to CentOS 4.7 and fudge a lot of settings and scripts to even get it to install – including turning off NumLock to fix the “font.properties not found” error! I used a combination of instructions here for Fedora Core 2 and here for RHEL 4ASu4.

I found a fix for the 100% CPU load on CentOS 4.7 – pass the “divider=10” kernel parameter to grub; also turn off acpid and cpuspeed in the service menu. Still no fix for XP64, and strangely enough the issue doesn’t occur on CentOS 5.2

After all that installing, I found that the VDI’s were around 14Gb, as the ~4Gb from the deleted cpio’s hadn’t been free’d! So I had a hunt around the forums and found a utility called zerofree that zeroes any unused sectors. I found it best to run it from a rescue CD (in my case RHEL 5.0), remounting the root partition as readonly first:

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mount -n -o remount,ro -t ext3 /dev/sda3 /
zerofree -v /dev/sda3

Then shutdown the VM, and on the host run:

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VBoxManage modifyhd centos47.vdi compact```
Which after a few minutes of disk chugging saved between 2 and 5Gb per VDI!
Last night I watched [Death Race](http://uk.imdb.com/title/tt0452608/), which I actually thought was a lot better than the original Death Race 2000.
The gas has been installed and the plumber has been to measure up, so installation of radiators etc. should start tomorrow for the next two weeks.