backdown hash

backdown hash [OPTIONS]

Options#

--jobs <JOBS>

Readers per device; 1 suits spinning disks, raise it for SSDs. Default: 1.

--retry-errors

Retry files that failed to read last time.

Also takes the global options --db and --local.

Good to know#

Hashes only what could be a duplicate: a file whose size no other file shares is never read. Then a sample (the first, middle and last 64 KiB) and, for files whose samples still match, the full SHA-256. Files on drives that aren't connected wait for them. See Hashes and proof.

Examples#

backdown hash
# an SSD: two readers per device
backdown hash --jobs 2
# try the files that couldn't be read last time again
backdown hash --retry-errors

See also#

• Hashes and proof