If I picked up the phone, called any IT administrator I know, and asked what technical part of their job they like the least, the answer would almost invariably be backups.
Nobody likes backups. In the complex world of mixed physical and virtual environments, it sometimes seems nearly impossible to build a backup regimen that just works every time. Instead, it's much more common to see a few resources fail to back up or to get some kind of ambiguous error that takes hours to properly diagnose and resolve.
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Too often, the amount of effort required to yield even the appearance of a consistently successful backup rotation takes so many hours that it crowds out other crucial tasks -- such as testing.