On large systems with many users, you need to control the amount of disk space a user has access to. Disk quotas are designed for this purpose. Quotas, managed per each partition, can be set for both individual users as well as groups; quotas for the group need not be as large as the aggregate quotas for the individuals in the groups. When files are created, both a user and a group own them; ownership of the files is always part of the metadata about the files. This makes quotas based on both users and groups easy to manage. Note Disk quota management is never done on a home system and rarely, if ever, done on a small office system. To manage disk quotas, you must have the quota package installed on your system; it is usually installed by default. Quota management with Fedora is not enabled by default and has traditionally been enabled and configured manually by system administrators. Sysadmins use the family of quota commands, such as quotacheck to initialize the quota database files, edquota to set and edit user quotas, setquota to configure disk quotas, and quotaon or quotaoff to control the service. (Other utilities include warnquota for automatically sending mail to users over their disk space usage limit.) Implementing QuotasTo reiterate, quotas might not be enabled by default, even if the quota software package is installed on your system. When quotas are installed and enabled, you can see which partitions have either user quotas, group quotas, or both by looking at the fourth field in the /etc/fstab file. For example, one line in /etc/fstab shows that quotas are enabled for the /home partition: /dev/hda5 /home ext3 defaults,usrquota,grpquota 1 1 The root of the partition with quotas enabled will have the files aquota.user or aquota.group in them (or both files, if both types of quotas are enabled), and the files will contain the actual quotas. The permissions of these files should be 600 so that users cannot read or write to them. (Otherwise, users would change them to allow ample space for their music files and Internet art collections.) To initialize disk quotas, the partitions must be remounted. This is easily accomplished with the following: # mount -o ro,remount partition_to_be_remounted mount_point The underlying console tools (complete with man pages) are
Manually Configuring QuotasManual configuration of quotas involves changing entries in your system's file system table, /etc/fstab, to add the usrquota mount option to the desired portion of your file system. As an example in a simple file system, quota management can be enabled like this: LABEL=/ / ext3 defaults,usrquota 1 1 Group-level quotas can also be enabled by using the grpquota option. As the root operator, you must then create a file (using our example of creating user quotas) named aquota.user in the designated portion of the file system, like so: # touch /quota.user You should then turn on the use of quotas using the quotaon command: # quotaon -av You can then edit user quotas with the edquota command to set hard and soft limits on file system use. The default system editor (vi unless you change your EDITOR environment variable) will be launched when editing a user's quota. Any user can find out what her quotas are with $ quota -v Note There are no graphical tools supported by Fedora that can be used to configure disk quotas. A Quota mini-HOWTO is maintained at http://www.tldp.org/HOWTO/mini/Quota.html.
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