Restoring everything from backups is very hard. Something that can make restore-from-backups harder, and that I've seen happen, is when the backup/restore syst

Restoring everything from backups is very hard. Something that can make restore-from-backups harder, and that I've seen happen, is when the backup/restore systems themselves get destroyed by the same black swan event. Then you have to first recover those by doing fresh installs, and you have to have all the people on hand who know what the configurations would have been to be able to then use the backup library. Then you have to begin restoring a few target systems to check that everything is OK with the restore process, then you have to restore everything though you'll be limited by the restore system's bandwidth. How could this happen? Well, a disgruntled employee could make it happen. It happened at Paine Webber in 2002 [0]. In that case the attacker left a time bomb in the boot process on all systems they could reach, and that included the backup/restore servers. Worse, the time bomb was in the backups themselves, so restored systems ate themselves as soon as they were booted, which slowed down the recovery process. [0] https://www.independent.co.uk/news/business/news/disgruntled-worker-tried-to-cripple-ubs-in-protest-over-32-000-bonus-481515.html https://www.justice.gov/archive/criminal/cybercrime/press-releases/2002/duronioIndict.htm