Guidelines for Setting Up Quotas

Before you set up quotas, you need to determine how much space and how many inodes to allocate to each user. If you want to be sure that the total file system space is never exceeded, you can divide the total size of the file system between the number of users. For example, if three users share a 100-Mbyte slice and have equal disk space needs, you could allocate 33 Mbytes to each user.

In environments where not all users are likely to push their limits, you might want to set individual quotas so that they add up to more than the total size of the file system. For example, if three users share a 100-Mbyte slice, you could allocate 40 Mbytes to each.

When you have established a quota for one user by using the edquota command, you can use this quota as a prototype to set the same quota for other users on the same file system.

Before you turn on the quotas, you must first configure the UFS file systems for the quotas, establish quotas for each user, and run the quotacheck command to check for consistency between current disk usage and quota files. Also, if systems are rebooted infrequently, it is a good idea to periodically run the quotacheck command.

The quotas you set up with the edquota command are not enforced until you turn them on by using the quotaon command. If you have properly configured the quota files, the quotas are turned on automatically each time a system is rebooted and the file system is mounted.

Setting Up Quotas (Task Map)

How to Configure File Systems for Quotas

1. Become superuser.

2. Edit the /etc/vfstab file and add rq to the mount options field for each UFS file system that will have quotas.

3. Change directory to the root of the file system that will have quotas.

4. Create a file named quotas.

   # touch quotas

5. Change permissions to read/write for root access only.

   # chmod 600 quotas

Examples--Configuring File Systems for Quotas

The following /etc/vfstab example shows that the /export/home directory from the system pluto is mounted as an NFS file system on the local system. You can tell quotas are enabled by the rq entry under the mount options column.

#device           device   mount       FS    fsck   mount   mount
#to mount         to fsck  point       type  pass   at boot options
#
pluto:/export/home -       /export/home nfs    -     yes    rq

The following example line from /etc/vfstab shows that the local /work directory is mounted with quotas enabled, signified by the rq entry under the mount options column.

#device           device            mount  FS   fsck mount   mount
#to mount         to fsck           point  type pass at boot options
#
/dev/dsk/c0t4d0s0 /dev/rdsk/c0t4d0s0 /work ufs  3    yes     rq

How to Set Up Quotas for a User

1. Become superuser.

2. Use the quota editor to create a temporary file that contains one line of quota information for each mounted UFS file system that has a quotas file in the file system's root directory.

   # edquota username

   Where username is the user for whom you want to set up quotas.

3. Change the number of 1-Kbyte disk blocks (both soft and hard) and the number of inodes (both soft and hard) from 0 (the default) to the quotas you specify for each file system.

4. Verify the user's quota.

   # quota -v username

   -v	Displays the user's quota information on all mounted file systems where quotas exist.
   username	Specifies the user name to view quota limits.

Examples--Setting Up Quotas for a User

The following example shows the contents of the temporary file opened by edquota on a system where /files is the only mounted file system containing a quotas file in the root directory.

fs /files blocks (soft = 0, hard = 0) inodes (soft = 0, hard = 0)

The following example shows the same line in the temporary file after quotas have been set up.

fs /files blocks (soft = 50, hard = 60) inodes (soft = 90, hard = 100)

How to Set Up Quotas for Multiple Users

1. Become superuser.

2. Use the quota editor to apply the quotas you already established for a prototype user to the additional users you specify.

   # edquota -p prototype-user username ...

   prototype-user	User name of the account for which you have set up quotas.
   username ...	Specifies one or more user names of additional accounts.

Example--Setting Up Prototype Quotas for Multiple Users

The following example shows how to apply the quotas established for user bob to users mary and john.

# edquota -p bob mary john

How to Check Quota Consistency

Note - To ensure accurate disk data, the file systems being checked should be quiescent when you run the quotacheck command manually. The quotacheck command is run automatically when a system is rebooted.

1. Become superuser.

2. Run a consistency check on UFS file systems.

   # quotacheck [-va] filesystem

   -v	(Optional) Identifies the disk quotas for each user on a particular file system.
   -a	Checks all file systems with an rq entry in the /etc/vfstab file.
   filesystem	Specifies the file system to check.

   See quotacheck(1M) for more information.

Example--Checking Quota Consistency

The following example shows how to check quotas for the /export/home file system on the /dev/rdsk/c0t0d0s7 slice. The /export/home file system is the only file system with an rq entry in the /etc/vfstab file.

# quotacheck -va
*** Checking quotas for /dev/rdsk/c0t0d0s7 (/export/home)

How to Turn On Quotas

1. Become superuser.

2. Turn on file system quotas.

   # quotaon [-v] -a filesystem ...

   -v	Displays a message for each file system after quotas are turned on.
   -a	Turns on quotas for all file systems with an rq entry in the /etc/vfstab file.
   filesystem ...	Turns on quotas for one or more file systems that you specify. More than one file system is specified by separating each file system name with a space.

Example--Turning On Quotas

The following example shows how to turn quotas on for the file systems on the /dev/dsk/c0t4d0s7 and /dev/dsk/c0t3d0s7 slices.

# quotaon -v /dev/dsk/c0t4d0s7 /dev/dsk/c0t3d0s7
/dev/dsk/c0t4d0s7: quotas turned on
/dev/dsk/c0t3d0s7: quotas turned on

Checking Quotas

After you have set up and turned on disk quotas and inode quotas, you can check for users who exceed their quotas. In addition, you can check quota information for entire file systems.

The following table describes the commands you use to check quotas.

Table 17-2 Commands for Checking Quotas