This risk can be mitigated by: a) Creating multiple DVDs each time you back up (if your dataset is small enough and stable enough that DVDs are an option, doin

This risk can be mitigated by: a) Creating multiple DVDs each time you back up (if your dataset is small enough and stable enough that DVDs are an option, doing two burns seems like an acceptable burden to me). b) Storing parity files[0] on the DVDs to allow you to actually recover from bit rot and disk damage. [0] http://en.wikipedia.org/wiki/Parchive http://en.wikipedia.org/wiki/Parchive