Backup media, strategies and pitfalls

[qxp]

What do you use for backups ? How safe are they ? Let's discuss !

Here is what I use:

• USB stick for relatively small files
• SSD drives for moderately large files - at the moment 2 or 4TB SSDs are cheaper per GB than SD cards. One caveat is that as of now (2024) larger capacity QLC drives need to be powered on once a year or so to be sure that data does not decay.
• Spinning magnetic media - good for large data, stores data for longer periods, but susceptible to mechanical damage and magnetic fields. Any opinions on CMR vs Shingled ?
• Optical media - I use M-disk because it promises long term storage. Unfortunately, the largest I got is 100GB. So for relatively small files.
• Print on paper - for tiny text files Inkjet can bleach over time or be washed out by moisture. Laser printing on plastic (like transparencies) probably lasts longer - is anyone doing that ?
• Upload to Internet - for public code and data
• Upload to cloud
• I don't use tape anymore - the capacity is not there, expensive, and can lose data due to tape stretching.

A good strategy is to use multiple media, ideally in separate physical locations. RAID is nice for very large storage, but might be problematic if there is a need to retrieve data from really old volume, especially if using hardware controller.

Anything I missed ? Any new hardware to consider ?