Provided by: xfsprogs_5.13.0-1ubuntu2_amd64 bug

NAME

       xfs_quota - manage use of quota on XFS filesystems

SYNOPSIS

       xfs_quota [ -x ] [ -f ] [ -p prog ] [ -c cmd ] ... [ -d project ] ... [ -D projects_file ]
       [ -P projid_file ] [ path ... ]
       xfs_quota -V

DESCRIPTION

       xfs_quota is a utility for reporting and editing various aspects of filesystem quota.

       The options to xfs_quota are:

       -c cmd    xfs_quota commands may be run interactively (the default) or as arguments on the
                 command  line.  Multiple -c arguments may be given.  The commands are run in the
                 sequence given, then the program exits.

       -p prog   Set the program name for prompts and some error messages, the default  value  is
                 xfs_quota.

       -x        Enable  expert  mode.  All of the administrative commands (see the ADMINISTRATOR
                 COMMANDS section below) which  allow  modifications  to  the  quota  system  are
                 available only in expert mode.

       -f        Enable  foreign  filesystem  mode.   A limited number of user and administrative
                 commands are available for use on some foreign (non-XFS) filesystems.

       -d project
                 Project names or numeric identifiers may be specified with  this  option,  which
                 restricts the output of the individual xfs_quota commands to the set of projects
                 specified. Multiple -d arguments may be given.

       -D projects_file
                 Specify a  file  containing  the  mapping  of  numeric  project  identifiers  to
                 directory trees.  /etc/projects as default, if this option is none.

       -P projid_file
                 Specify  a file containing the mapping of numeric project identifiers to project
                 names.  /etc/projid as default, if this option is none.

       -V        Prints the version number and exits.

       The optional path argument(s) can be used to specify mount points or  device  files  which
       identify  XFS  filesystems.  The  output of the individual xfs_quota commands will then be
       restricted to the set of filesystems specified.

       This manual page is divided  into  two  sections  -  firstly,  information  for  users  of
       filesystems  with quota enabled, and the xfs_quota commands of interest to such users; and
       then information which is useful only to administrators of XFS filesystems using quota and
       the quota commands which allow modifications to the quota system.

       Note  that common to almost all of the individual commands described below are the options
       for specifying which quota types are of interest - user  quota  (-u),  group  quota  (-g),
       and/or  project  quota (-p).  Also, several commands provide options to operate on "blocks
       used" (-b), "inodes used" (-i), and/or "realtime blocks used" (-r).

       Many commands also have extensive online help. Use the help command for  more  details  on
       any command.

QUOTA OVERVIEW

       In  most computing environments, disk space is not infinite.  The quota subsystem provides
       a mechanism to control usage of disk space.  Quotas can be set for each individual user on
       any/all  of the local filesystems.  The quota subsystem warns users when they exceed their
       allotted limit, but allows some extra space for current work (hard limit/soft limit).   In
       addition,  XFS  filesystems  with limit enforcement turned off can be used as an effective
       disk usage accounting system.

   Users' View of Disk Quotas
       To most users, disk quotas are either of no concern or a  fact  of  life  that  cannot  be
       avoided.   There  are  two possible quotas that can be imposed - a limit can be set on the
       amount of space a user can occupy, and there may  be  a  limit  on  the  number  of  files
       (inodes) they can own.

       The  quota  command  provides  information  on the quotas that have been set by the system
       administrators and current usage.

       There are four numbers for each limit:  current usage, soft limit (quota), hard limit, and
       time  limit.   The  soft  limit  is  the  number  of 1K-blocks (or files) that the user is
       expected to remain below.  The hard limit cannot be exceeded.  If a user's  usage  reaches
       the  hard  limit,  further requests for space (or attempts to create a file) fail with the
       "Quota exceeded" (EDQUOT) error.

       When a user exceeds the soft limit, the timer is enabled.  Any time the quota drops  below
       the  soft limits, the timer is disabled.  If the timer pops, the particular limit that has
       been exceeded is treated as if the hard limit has been reached, and no more resources  are
       allocated  to  the user.  The only way to reset this condition, short of turning off limit
       enforcement or increasing the limit, is to reduce usage below quota.  Only  the  superuser
       (i.e.  a  sufficiently  capable process) can set the time limits and this is done on a per
       filesystem basis.

   Surviving When the Quota Limit Is Reached
       In most cases, the only way for a user to recover from over-quota conditions is  to  abort
       whatever  activity  is  in  progress  on the filesystem that has reached its limit, remove
       sufficient files to bring the limit back below quota, and retry the failed program.
       However, if a user is in the editor and a write fails because of an over quota  situation,
       that  is  not a suitable course of action.  It is most likely that initially attempting to
       write the file has truncated its previous contents, so if the editor  is  aborted  without
       correctly  writing  the  file, not only are the recent changes lost, but possibly much, or
       even all, of the contents that previously existed.
       There are several possible safe exits for a user caught in this situation.  They  can  use
       the  editor  shell  escape  command  to examine their file space and remove surplus files.
       Alternatively, using sh(1), they can suspend the editor, remove some  files,  then  resume
       it.   A third possibility is to write the file to some other filesystem (perhaps to a file
       on /tmp) where the user's quota has not been exceeded.  Then after  rectifying  the  quota
       situation, the file can be moved back to the filesystem it belongs on.

   Default Quotas
       The  XFS  quota  subsystem  allows  a  default quota to be enforced for any user, group or
       project which does not have a quota limit explicitly set.  These limits are stored in  and
       displayed as ID 0's limits, although they do not actually limit ID 0.

USER COMMANDS

       print  Lists  all  paths  with  devices/project  identifiers.  The path list can come from
              several places - the command line, the mount table, and the /etc/projects file.

       df     See the free command.

       quota [ -g | -p | -u ] [ -bir ] [ -hnNv ] [ -f file ] [ ID | name ] ...
              Show individual usage and limits, for a single user name or numeric user  ID.   The
              -h option reports in a "human-readable" format similar to the df(1) command. The -n
              option reports the numeric IDs rather than  the  name.  The  -N  option  omits  the
              header.  The  -v option outputs verbose information. The -f option sends the output
              to file instead of stdout.

       free [ -bir ] [ -hN ] [ -f file ]
              Reports filesystem usage, much like the df(1)  utility.   It  can  show  usage  for
              blocks,  inode,  and/or  realtime  block  space,  and  shows  used, free, and total
              available.  If project quota are in use  (see  the  DIRECTORY  TREE  QUOTA  section
              below),  it  will also report utilisation for those projects (directory trees). The
              -h option reports in a "human-readable" format. The -N option omits the header. The
              -f option outputs the report to file instead of stdout.

       help [ command ]
              Online help for all commands, or one specific command.

       quit   Exit xfs_quota.

       q      See the quit command.

QUOTA ADMINISTRATION

       The  XFS  quota  system  differs  to  that of other filesystems in a number of ways.  Most
       importantly, XFS considers quota information as filesystem metadata and uses journaling to
       provide a higher level guarantee of consistency.  As such, it is administered differently,
       in particular:

       1.     The quotacheck command has no effect on XFS  filesystems.   The  first  time  quota
              accounting  is  turned  on  (at  mount  time),  XFS  does  an  automatic quotacheck
              internally; afterwards, the quota system will always be completely consistent until
              quotas are manually turned off.

       2.     There is no need for quota file(s) in the root of the XFS filesystem.

       3.     XFS distinguishes between quota accounting and limit enforcement.  Quota accounting
              must be turned on at the time of mounting  the  XFS  filesystem.   However,  it  is
              possible  to  turn on/off limit enforcement any time quota accounting is turned on.
              The "quota" option to the mount command turns on both (user) quota  accounting  and
              enforcement.  The "uqnoenforce" option must be used to turn on user accounting with
              limit enforcement disabled.

       4.     Turning on quotas on the root filesystem is slightly different from the above.  For
              Linux  XFS,  the  quota  mount  flags  must be passed in with the "rootflags=" boot
              parameter.

       5.     It is useful to use the state to monitor the XFS quota subsystem at various  stages
              -  it  can  be  used  to see if quotas are turned on, and also to monitor the space
              occupied by the quota system itself..

       6.     There is a mechanism built into xfsdump that allows quota limit information  to  be
              backed up for later restoration, should the need arise.

       7.     Quota limits cannot be set before turning on quotas on.

       8.     XFS filesystems keep quota accounting on the superuser (user ID zero), and the tool
              will display the superuser's usage information.  However, limits are never enforced
              on the superuser (nor are they enforced for group and project ID zero).

       9.     XFS filesystems perform quota accounting whether the user has quota limits or not.

       10.    XFS  supports the notion of project quota, which can be used to implement a form of
              directory tree quota (i.e. to restrict a directory tree to only being able  to  use
              up  a  component of the filesystems available space; or simply to keep track of the
              amount of space used, or number of inodes, within the tree).

ADMINISTRATOR COMMANDS

       path [ N ]
              Lists all paths with devices/project identifiers or set the current path to the Nth
              list  entry  (the  current  path is used by many of the commands described here, it
              identifies the filesystem toward which a command is directed).  The path  list  can
              come from several places - the command line, the mount table, and the /etc/projects
              file.

       report [ -gpu ] [ -bir ] [ -ahntlLNU ] [ -f file ]
              Report  filesystem  quota  information.   This  reports  all  quota  usage  for   a
              filesystem, for the specified quota type (u/g/p and/or blocks/inodes/realtime).  It
              reports blocks in 1KB units by default. The -h option reports in a "human-readable"
              format  similar  to  the  df(1)  command.  The -f option outputs the report to file
              instead of stdout. The -a option reports on all filesystems.  By  default,  outputs
              the  name  of the user/group/project. If no name is defined for a given ID, outputs
              the numeric ID instead. The -n option outputs the numeric ID instead of  the  name.
              The  -L  and  -U  options  specify  lower  and  upper  ID  bounds to report on.  If
              upper/lower bounds are specified, then by default only the IDs will be displayed in
              output;  with  the  -l option, a lookup will be performed to translate these IDs to
              names. The -N option reports information without the header  line.  The  -t  option
              performs a terse report.

       state [ -gpu ] [ -av ] [ -f file ]
              Report  overall  quota  state  information.   This  reports  on  the state of quota
              accounting, quota enforcement, and the  number  of  extents  being  used  by  quota
              metadata  within  the  filesystem.  The -f option outputs state information to file
              instead of stdout. The -a option reports state on all filesystems and not just  the
              current path.

       limit  [ -g | -p | -u ] bsoft=N | bhard=N | isoft=N | ihard=N | rtbsoft=N | rtbhard=N -d |
              id | name
              Set quota block limits  (bhard/bsoft),  inode  count  limits  (ihard/isoft)  and/or
              realtime  block  limits  (rtbhard/rtbsoft). The -d option (defaults) can be used to
              set the default value that will be used, otherwise  a  specific  user/group/project
              name or numeric identifier must be specified.

       timer [ -g | -p | -u ] [ -bir ] value [ -d | id | name ]
              Allows  the  quota  enforcement  timeout  (i.e.  the amount of time allowed to pass
              before the soft limits are enforced as the hard limits) to be modified. The current
              timeout setting can be displayed using the state command.
              When setting the default timer via the -d option, or for id 0, or if no argument is
              given after value the value argument is a number of seconds indicating the relative
              amount of time after soft limits are exceeded, before hard limits are enforced.
              When  setting  any other individual timer by id or name, the value is the number of
              seconds from now, at which time the hard limits  will  be  enforced.   This  allows
              extending the grace time of an individual user who has exceeded soft limits.
              For value, units of 'minutes', 'hours', 'days', and 'weeks' are also understood (as
              are their abbreviations 'm', 'h', 'd', and 'w').

       warn [ -g | -p | -u ] [ -bir ] value -d | id | name
              Allows the quota warnings limit (i.e. the number of times a warning will be send to
              someone over quota) to be viewed and modified. The -d option (defaults) can be used
              to set the default time that will be used, otherwise a specific  user/group/project
              name  or numeric identifier must be specified.  NOTE: this feature is not currently
              implemented.

       enable [ -gpu ] [ -v ]
              Switches on quota enforcement for the filesystem identified by  the  current  path.
              This  requires  the  filesystem  to  have  been mounted with quota enabled, and for
              accounting to be currently active. The -v option (verbose) displays the state after
              the operation has completed.

       disable [ -gpu ] [ -v ]
              Disables  quota  enforcement,  while leaving quota accounting active. The -v option
              (verbose) displays the state after the operation has completed.

       off [ -gpu ] [ -v ]
              Permanently switches quota off for the filesystem identified by the  current  path.
              Quota  can  only  be  switched back on subsequently by unmounting and then mounting
              again.

       remove [ -gpu ] [ -v ]
              Remove any space allocated to quota metadata from the filesystem identified by  the
              current  path.   Quota  must  not be enabled on the filesystem, else this operation
              will report an error.

       dump [ -g | -p | -u ] [ -f file ]
              Dump out quota limit information for backup utilities, either  to  standard  output
              (default)  or  to  a  file.  This is only the limits, not the usage information, of
              course.

       restore [ -g | -p | -u ] [ -f file ]
              Restore quota limits from a backup file.  The file must be in the  format  produced
              by the dump command.

       quot [ -g | -p | -u ] [ -bir ] [ -acnv ] [ -f file ]
              Summarize  filesystem  ownership,  by  user, group or project.  This command uses a
              special XFS "bulkstat" interface to quickly scan an entire  filesystem  and  report
              usage  information.   This  command  can be used even when filesystem quota are not
              enabled, as it is a full-filesystem scan (it may also take a long time...). The  -a
              option  displays information on all filesystems. The -c option displays a histogram
              instead of a report. The -n option displays numeric IDs rather than names.  The  -v
              option  displays verbose information. The -f option send the output to file instead
              of stdout.

       project [ -cCs [ -d depth ] [ -p path ] id | name ]
              The -c, -C, and  -s  options  allow  the  directory  tree  quota  mechanism  to  be
              maintained.   -d  allows  one  to  limit  recursion  level  when processing project
              directories and -p allows one to specify project paths at command line ( instead of
              /etc/projects ). All options are discussed in detail below.

DIRECTORY TREE QUOTA

       The  project  quota  mechanism  in  XFS  can be used to implement a form of directory tree
       quota, where a specified directory and all of the files and subdirectories below it  (i.e.
       a tree) can be restricted to using a subset of the available space in the filesystem.

       A  managed  tree  must  be setup initially using the -s option to the project command. The
       specified project name  or  identifier  is  matched  to  one  or  more  trees  defined  in
       /etc/projects,  and these trees are then recursively descended to mark the affected inodes
       as being part of that tree.  This process sets an inode flag and the project identifier on
       every  file  in the affected tree.  Once this has been done, new files created in the tree
       will automatically be accounted to the tree based on their project identifier.  An attempt
       to  create  a  hard link to a file in the tree will only succeed if the project identifier
       matches the project identifier for the tree.  The xfs_io utility can be used  to  set  the
       project ID for an arbitrary file, but this can only be done by a privileged user.

       A  previously  setup  tree  can  be  cleared from project quota control through use of the
       project -C option, which will recursively descend the tree, clearing the  affected  inodes
       from project quota control.

       Finally,  the  project  -c option can be used to check whether a tree is setup, it reports
       nothing if the tree is correct, otherwise it reports the paths of inodes which do not have
       the project ID of the rest of the tree, or if the inode flag is not set.

       Option  -d can be used to limit recursion level (-1 is infinite, 0 is top level only, 1 is
       first level ... ).  Option -p adds possibility to specify project paths  in  command  line
       without  a  need  for /etc/projects to exist. Note that if projects file exists then it is
       also used.

EXAMPLES

       Enabling quota enforcement on an XFS filesystem (restrict  a  user  to  a  set  amount  of
       space).

            # mount -o uquota /dev/xvm/home /home
            # xfs_quota -x -c 'limit bsoft=500m bhard=550m tanya' /home
            # xfs_quota -x -c report /home

       Enabling  project  quota  on  an XFS filesystem (restrict files in log file directories to
       only using 1 gigabyte of space).

            # mount -o prjquota /dev/xvm/var /var
            # echo 42:/var/log >> /etc/projects
            # echo logfiles:42 >> /etc/projid
            # xfs_quota -x -c 'project -s logfiles' /var
            # xfs_quota -x -c 'limit -p bhard=1g logfiles' /var

       Same as above without a need for configuration files.

            # rm -f /etc/projects /etc/projid
            # mount -o prjquota /dev/xvm/var /var
            # xfs_quota -x -c 'project -s -p /var/log 42' /var
            # xfs_quota -x -c 'limit -p bhard=1g 42' /var

CAVEATS

       The XFS allocation mechanism will always reserve the  maximum  amount  of  space  required
       before  proceeding  with  an  allocation.   If  insufficient space for this reservation is
       available, due to the block quota limit being reached for example, this may result in  the
       allocation  failing  even  though  there  is sufficient space.  Quota enforcement can thus
       sometimes happen in situations where the user is under quota and the end  result  of  some
       operation would still have left the user under quota had the operation been allowed to run
       its course.  This additional overhead is typically in the range of tens of blocks.

       Both of these properties are unavoidable side effects of the way XFS operates,  so  should
       be kept in mind when assigning block limits.

BUGS

       Quota  support for filesystems with realtime subvolumes is not yet implemented, nor is the
       quota warning mechanism (the Linux warnquota(8)  tool  can  be  used  to  provide  similar
       functionality on that platform).

FILES

       /etc/projects       Mapping of numeric project identifiers to directories trees.
       /etc/projid         Mapping of numeric project identifiers to project names.

SEE ALSO

       df(1), mount(1), sync(2), projid(5), projects(5).  xfs(5).  warnquota(8),

                                                                                     xfs_quota(8)