Linux

~/.claude and ~/.codex mix config with logins and plaintext transcripts. Back up what you wrote, exclude credential files, and log in again on restore.

systemd in one container failed with "Too many open files", and Docker in another with "unable to create session key: disk quota exceeded". Neither was about files or disks: all the containers were spending the same per-user kernel quotas on the host.

RouterOS writes autosupout.rif after a crash and tells you to send it to MikroTik support. The file is zlib sections in a bit-reversed base64, and a short Python script turns it into the kernel oops, the log and the config. It also holds your secrets in plain text.