Are my other partitions safe from harm from an alpha/beta release?

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http://askubuntu.com – I am quite intrested in testing the latest alpha-3 of Ubuntu, however, performance in VirtualBox is slow and somewhat buggy (I know! It's an Alpha) - guest additions wern't installing, bad mouse intergration, etc. I would now like to test this release on my hard drive. But my main system (12.04) is also on this very same hard drive. Is this safe? Can the alpha touch my main partition? Are there any other risks? (HowTos)