$ Linux Command

Administration

quotacheck

Scan filesystems for disk usage and create quota files.

quotadiskfilesystemusagelimits

Additional Notes

quotacheck scans filesystems to create, check, and repair quota database files (aquota.user and aquota.group). It reads the filesystem's directory structure to determine current disk usage for each user and group, then writes this information to the quota record files.

System administrators use quotacheck when enabling quotas on a filesystem, after filesystem corruption that may have affected quota records, or periodically to synchronize quota records with actual disk usage. It is typically run before enabling quotas with quotaon.

Syntax

quotacheck [options] [filesystem...]

Parameters

  • filesystem: Mount point (e.g., /home) or device path (e.g., /dev/sda2).

Common Options

  • -a, --all: Check all filesystems with quota support enabled in /etc/fstab.
  • -u, --user: Create or update user quota files (aquota.user).
  • -g, --group: Create or update group quota files (aquota.group).
  • -c, --create-files: Create quota files if they do not exist.
  • -v, --verbose: Show detailed output during scanning.
  • -f, --force: Force checking even if quotas are enabled.
  • -m, --no-remount: Do not remount the filesystem read-only for the scan (use on active filesystems).
  • -n, --bad-ids: Skip checking for non-existent UIDs/GIDs.
  • -R, --exclude-root: Exclude the root filesystem when using -a.
  • -b, --no-backup: Do not back up old quota files.

Examples

quotacheck -avug

Scan all filesystems with quotas enabled, updating user and group quota files.

quotacheck -cuv /home

Create and update quota files for /home with verbose output.

quotacheck -m /var

Check /var without remounting it (safe for active filesystems).

quotacheck -f /home

Force quota file checking even if quota is already active.

quotacheck -avugm

Recommended safe command: check all quota-enabled filesystems without remounting.

Practical Notes

  • Run quotacheck before enabling quotas with quotaon. Afterward, verify with repquota -a.
  • The -m flag is important on production systems. Without it, quotacheck attempts to remount the filesystem read-only, which may disrupt active users.
  • Quota files are typically named aquota.user and aquota.group and are stored in the root of the filesystem.
  • Quotas must be enabled in /etc/fstab with the usrquota and/or grpquota mount options.
  • On very large filesystems, quotacheck can take significant time. Run during maintenance windows.
  • If quotacheck reports inconsistencies, you may need to unmount and run fsck on the filesystem before retrying.