“Miscellaneous § November 2016 Data Loss Postmortem”, Gwern2009-08-05 (, ; similar)⁠:

Misc thoughts, memories, proto-essays, musings, etc.

In late November 2016, my Acer laptop broke and also corrupted the encrypted filesystem on the SSD, which apparently due to design decisions is very easily broken. Because I had been changing my backup strategy to use an new encryption key and had been lax about my manual backups, this made the most recent encrypted backups undecryptable as well, causing data loss back at least 2 weeks. I review how all this came to pass despite my careful backups, and my countermeasures: a new higher quality laptop, making backups of encrypted filesystem headers as well as the contents, and buying faster external drive enclosures.

Key lesson: if you use LUKS-encrypted Linux filesystems, know that they are super-fragile! You should backup a copy of the LUKS header (by running a command like sudo cryptsetup luksHeaderBackup /dev/sda5 –header-backup-file luks-header.bin.crypt) to avoid the header becoming corrupted & all data destroyed.