ITunes Match deleted songs from my hard drive. I had to re-rip them. How can I stop this from happening?

Question

iTunes Match deleted songs from my hard drive. How can I prevent this from happening if I try it again?

Answer 1

iTunes Match can in no way be considered a backup service, this is due to the inexact nature of the 'matching process' (see https://discussions.apple.com/docs/DOC-4112, for more detail).
Loss of files from a Disk is certainly possible through media failure.  However, the extent of iTunes Match capacity is solely to influence the content of the cloud.  Perhaps there was a coincident, or pre-existing, failure of the disk which was simply exposed by the iTunes Match interrogation of the disk content.
There are certainly other services which depending upon your goal may work well.  For example, Google Play with gBeats IOS App works very well.  My use of Match is to synchronise across several computers and to drive Apple TV and an IOS device - other IOS devices still use sync for specific music and are complimented by gBeats for access to the full library when local mobile signal strength is high.
The strong advice to always start with a secure backup remains but if your primary concern is iTunes Match interfering with physical disk content you can relax - it simply does not have this ability.  (Apology to Sherlock, further investigation required).