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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

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.