$ Linux Command

System

updatedb

Update the locate/mlocate database.

locatedatabasesearchfilesindex

Additional Notes

updatedb builds or refreshes the database used by the locate command. It scans the filesystem (subject to configured exclusions) and indexes filenames so that locate can return results almost instantly. The database is typically stored at /var/lib/mlocate/mlocate.db and is updated daily via a systemd timer or cron job.

The command traverses the filesystem according to its configuration file /etc/updatedb.conf, which controls which filesystems to include or exclude, which directories to skip, and which bind mounts to follow. By default, it excludes pseudo-filesystems (/proc, /sys, /dev) and network filesystems. Changes to the configuration take effect on the next run.

Syntax

updatedb [options]

Parameters

  • options: Flags that change how updatedb behaves.
  • target: Optional file, device, interface, user, service, or command target when the command supports one.

Common Options

  • -U PATH, --database-root PATH: Only index files under PATH instead of the root filesystem.
  • -o FILE, --output FILE: Write the database to FILE instead of the default location.
  • -e DIRECTORY, --exclude DIRECTORY: Exclude the given directory from indexing (can be specified multiple times, colon-separated, or use PRUNEPATHS in the config).
  • -f FILESYSTEM, --add-prunefs FILESYSTEM: Exclude the given filesystem type.
  • -l, --localpaths: Limit the search to local filesystems (as defined by LOCALPATHS in config).
  • -n, --netpaths: Also index network filesystem paths.
  • -v, --verbose: Show progress during indexing.

Examples

sudo updatedb

Update the locate database for the entire system.

updatedb -U /home -o /tmp/home.db

Index only /home and save the database to a custom location.

sudo updatedb -v

Update the database with verbose progress output.

Practical Notes

  • updatedb must typically be run as root to scan directories that ordinary users cannot read.
  • Search with locate afterward: locate filename.
  • Exclude noisy directories like build artifacts and caches by editing /etc/updatedb.conf.
  • The database is usually updated daily; you can force a manual update with sudo updatedb.
  • For real-time file searching, use find or fdfind. locate/updatedb is best for quick filename lookups on a snapshot of the filesystem.