Comment by leptons

For "Hot" backup I have two mirrored RAID 10 systems (one in a detached garage, so technically "off site"), so I could lose up to 4 drives without losing any data. That's where the cheap hard drive storage comes in handy. One of those systems runs 24/7, so I pay a premium for spinning disks because availability is what that's all about. The "off site" system kind of a cold-storage backup system with the LTO tape drive in it. That system does weekly backups, and it also acts like a buffer for all the less "hot" data that mostly goes almost straight to tape until it's needed again.

I waited for years for used datacenter tape drives to become affordable. The math for DVD or hard drive cold storage didn't make sense, especially since I like redundant backups so it's 2x the cost. Tapes were designed for cold storage and it's faster and more cost effective than backing up to hard drives. Maybe I'll change my tune someday after a tape unravelling disaster if that ever happens, but in 2 years it's been pretty reliable.