Wikibon has often stated that application RPO/RTO requirements should be the primary drivers for backup, restore and disaster recovery technology. VTLs address the local backup and restore requirements extremely well, and are usually implemented so that the B/R software is not even aware of the VTL’s existence; the VTL looks like a set of tape drives.
Users should be aware that this technology implementation can mean that the disaster recovery component of the RPO/RTO application requirement is not adequately addressed; the increased elapsed time for the data to be taken offsite and the manual procedures required to ensure that tapes are created and shipped can severely compromise disaster recovery capabilities.
Hybrid technologies, where the VTLs are equipped with tape drives, provide a potential solution to this problem. However, to be fully effective, this technology will have to be better integrated into the B/R software and procedures.
Action Item: Nassim Nicholas Tale’s book “The Black Swan: The Impact of the Highly Improbable” (2007) graphically illustrates how short-term certain rewards (in this case easier local restores) will prevent people from guarding against lower probabilities of a disaster (in this case loss of a large amount of data). Organizations need to explicitly factor in the impact of delaying getting data offsite, and integrate technologies to minimize these risks.
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