Copying the database file is fairly safe, especially for an application that's likely to be read-mostly like WordPress. It could fail if the database was large

Copying the database file is fairly safe, especially for an application that's likely to be read-mostly like WordPress. It could fail if the database was large enough that copying it took a nontrivial amount of time, and the database was modified during the copy operation -- but even then, there's a fair chance it'd be recoverable. SQLite is pretty resilient. The "safe" way of doing the backup would be: sqlite3 wordpress.db ".backup wordpress-backup.db" which writes out a new copy of the database file. Restoring the database would be as simple as renaming the backup to the main file -- the backup is a "real" database file; there's no import operation required.