Simple howtos

This collection of mini howtos is a dynamic copy of the Unix Toolbox. This page extracts the XML content directly from the original XHTML DOM and displays only the requested node. Source code here (use "save as").
Unix Toolbox revision 14.4
Copyright (c) 2007-2012 Colin Barschel. Some rights reserved under Creative Commons [Attribution - Share Alike]
System
Processes
File System
Network
SSH SCP
VPN with SSH
RSYNC
SUDO
Encrypt Files
Encrypt Partitions
SSL Certificates
CVS
SVN
Useful Commands
Install Software
Convert Media
Printing
Databases
Disk Quota
Shells
Scripting
Programming
Online Help

Disk Quota

A disk quota allows to limit the amount of disk space and/or the number of files a user or (or member of group) can use. The quotas are allocated on a per-file system basis and are enforced by the kernel.

Linux setup

The quota tools package usually needs to be installed, it contains the command line tools.
Activate the user quota in the fstab and remount the partition. If the partition is busy, either all locked files must be closed, or the system must be rebooted. Add usrquota to the fstab mount options, for example:
/dev/sda2     /home    reiserfs     rw,acl,user_xattr,usrquota 1 1
# mount -o remount /home
# mount                              # Check if usrquota is active, otherwise reboot
Initialize the quota.user file with quotacheck.
# quotacheck -vum /home
# chmod 644 /home/aquota.user        # To let the users check their own quota
Activate the quota either with the provided script (e.g. /etc/init.d/quotad on SuSE) or with quotaon:
quotaon -vu /home
Check that the quota is active with:
quota -v

FreeBSD setup

The quota tools are part of the base system, however the kernel needs the option quota. If it is not there, add it and recompile the kernel.
options QUOTA
As with Linux, add the quota to the fstab options (userquota, not usrquota):
/dev/ad0s1d    /home    ufs     rw,noatime,userquota    2  2
# mount /home                        # To remount the partition
Enable disk quotas in /etc/rc.conf and start the quota.
# grep quotas /etc/rc.conf
enable_quotas="YES"                  # turn on quotas on startup (or NO).
check_quotas="YES"                   # Check quotas on startup (or NO).
# /etc/rc.d/quota start

Assign quota limits

The quotas are not limited per default (set to 0). The limits are set with edquota for single users. A quota can be also duplicated to many users. The file structure is different between the quota implementations, but the principle is the same: the values of blocks and inodes can be limited. Only change the values of soft and hard. If not specified, the blocks are 1k. The grace period is set with edquota -t. For example:
# edquota -u colin

Linux

Disk quotas for user colin (uid 1007):
  Filesystem         blocks       soft       hard     inodes     soft     hard
  /dev/sda8            108       1000       2000          1        0        0

FreeBSD

Quotas for user colin:
/home: kbytes in use: 504184, limits (soft = 700000, hard = 800000)
   inodes in use: 1792, limits (soft = 0, hard = 0)

For many users

The command edquota -p is used to duplicate a quota to other users. For example to duplicate a reference quota to all users:
# edquota -p refuser `awk -F: '$3 > 499 {print $1}' /etc/passwd`
# edquota -p refuser user1 user2     # Duplicate to 2 users

Checks

Users can check their quota by simply typing quota (the file quota.user must be readable). Root can check all quotas.
# quota -u colin                     # Check quota for a user
# repquota /home                     # Full report for the partition for all users