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Average media lifespan:

  • Optical (CD, DVD, Blu-ray) few months to 50+ years depending on type and quality (not big enough)
  • Hard drives 2 to 8 years (unreliable)
  • Solid state 1 to 10 years (expensive)

Beware of data rot

Consider BTRFS

  • RAID 1 is good
  • Georedundancy is good
  • RAID 1 and georedundancy is better

Don’t store anything you care about compressed

  • When cataloging backups with tree or something like that, it’s best not to forget hidden files and to do it recursively. So, use the proper flags.
  • Regarding corrupt archives, extract and pray. CRC is a problem; if a compressed archive is corrupted, usually the whole thing goes. An uncompressed archive means that only the corrupted file is an isolate incident. I have no real good solution for it yet.
  • For quick reference, in the order of tightest compression: 7z > bzip2 > gzip
  • dd if=/dev/cdrom of=example.iso
  • To test 4, create a folder “test”: mount -t iso9660 -o loop example.iso /home/sif/Desktop/test

Time is crucial for rotating backups

To survive solar flare and other EMP types of attacks… just print it all out

Any long term backup solution must consider privacy and quantum computing.