HDD vs SSD vs Flash

SSD as long-term storage

SSDs tend to have a longer MTBF than HDD (NVMe also tends to be longer than SATA SSD). However, without being connected to a stable power supply, the data would arguably survive for somewhere between a few months and a few years due to the natural degradation inherent in the quantum physics underlying SSD technology.. 

If you want to store the data on a shelf, long-term, without power then HDD or high quality Optical (e.g. Blu-Ray) may be, theoretically, a better choice. 

If you keep the drive plugged in and monitored, especially if it is part of a RAID configuration, then SSD and HDD are more evenly matched (you will, theoretically, need to swap out less SSDs due to failure, but you will likely pay more for each one compared to HDD. HDDs will consume more power, but SSDs can be sensitive to temperature and power fluctuations. In the event of drive failure, data recovery from HDD tends to have a higher chance of success).

All electronic storage is vulnerable to other risk like solar storms, fire, water or obsolesence.

If you print out the data using good quality paper and ink and protect the paper from damp, UV, and fire then you could realistically expect the data to survive  for several hundred years.

SAN vs NAS

CMR vs SMR

• In Conventional Magnetic Recording (CMR) tracks are adjacent to each other with a small gap between.

• In Shingled Magnetic Recording (SMR) tracks slightly overlap (like roof shingles). This allows for more tracks and thus higher capacity but leads to old data being overwritten. To avoid data loss the overwritten data must be written somewhere else. This is not really an issue for a user PC or laptop, since there is plenty of idle time to allow for this housekeeping. However, in a constant I/O environment there is likely to be a noticeable performance hit.

Identifying CMR/SMR

Database Storage

Acronyms

Bibliography