quotacheck – Scan a file system for disk usage – scan filesystem, verifyes & updates quota info
quotacheck [ -gubcfinvdMmR ] [ -F quota-format ] -a | filesystem
quotacheck examines each filesystem, builds a table of current disk usage, and compares this table against that recorded in the disk quota file for the filesystem (this step is ommitted if option -c is speci- fied). If any inconsistencies are detected, both the quota file and the current system copy of the incorrect quotas are updated (the latter only occurs if an active filesystem is checked which is not advised). By default, only user quotas are checked. quotacheck expects each filesystem to be checked to have quota files named [a]quota.user and [a]quota.group located at the root of the associated filesystem. If a file is not present, quotacheck will create it. If the quota file is corrupted, quotacheck tries to save as much data as possible. Rescuing data may need user intervention. With no addi- tional options quotacheck will simply exit in such a situation. When in interactive mode (option -i) , the user is asked for advice. Advice can also be provided from command line (see option -n) , which is useful when quotacheck is run automatically (ie. from script) and failure is unacceptable. quotacheck should be run each time the system boots and mounts non- valid filesystems. This is most likely to happen after a system crash. It is strongly recommended to run quotacheck with quotas turned off for the filesystem. Otherwise, possible damage or loss to data in the quota files can result. It is also unwise to run quotacheck on a live filesystem as actual usage may change during the scan. To prevent this, quotacheck tries to remount the filesystem read-only before starting the scan. After the scan is done it remounts the filesystem read-write. You can disable this with option -m. You can also make quotacheck ignore the failure to remount the filesystem read-only with option -M.
-b Forces quotacheck to make backups of the quota file before writ- ing the new data. -v quotacheck reports its operation as it progresses. Normally it operates silently. If the option is specified twice, also the current directory is printed (note that printing can slow down the scan measurably). -d Enable debugging mode. It will result in a lot of information which can be used in debugging the program. The output is very verbose and the scan will be slow. -u Only user quotas listed in /etc/mtab or on the filesystems spec- ified are to be checked. This is the default action. write to a filesystem while scanning. -m Don't try to remount filesystem read-only. See comment with option -M. -i Interactive mode. By default quotacheck exits when it finds an error. In interactive mode user is asked for input instead. See option -n. -n If the quota files become corrupted, it is possible for dupli- cate entries for a single user or group ID to exist. Normally in this case, quotacheck exits or asks user for input. When this option is set, the first entry found is always used (this option works in interactive mode too). -F format-name Check and fix quota files of specified format (ie. don't perform format auto-detection). This is recommended as detection might not work well on corrupted quota files. Possible format names are: vfsold (version 1 quota), vfsv0 (version 2 quota), rpc (quota over NFS), xfs (quota on XFS filesystem) -a Check all mounted non-NFS filesystems in /etc/mtab -R When used together with the -a option, all filesystems except for the root filesystem are checked for quotas.