Installation guide

7.7.3.1 Hard and Soft Quota Limits
File systems can have both soft and hard quota limits. When a hard limit
is reached, no more disk space allocations or file creations that would
exceed the limit are allowed. The soft limit may be reached for a period of
time (called the grace period). If the soft limit is reached for an amount of
time that exceeds the grace period, no more disk space allocations or file
creations are allowed until enough disk space is freed or enough files are
deleted to bring the disk space usage or number of files below the soft limit.
_____________________ Caution _____________________
With both hard and soft limits, you can end up with a
partially-written file if the quota limit is reached while you are
writing to the file.
If you are in an editor and exceed a quota limit, do not abort the editor or
write the file because data may be lost. Instead, use the editor exclamation
point (!) shell escape command to remove files. You can also write the file
to another file system, such as /tmp, remove files from the file system
whose quota you reached, and then move the file back to that file system.
It is important to note that a hard limit is one more unit (blocks, files, or
inodes) than will be allowed when the quota limit is active. The quota is up
to, but not including the limit. For example, if you set a hard limit of
10,000 disk blocks for each user account in a file system, an account
reaches the hard limit when 9,999 disk blocks have been allocated. If you
want a maximum of 10,000 complete blocks for the user account, you must
set the hard limit to 10,001.
7.7.3.2 Activating File System Quotas
To activate quotas on a UNIX file system, perform the following steps.
1. Configure the system to include the disk quota subsystem by editing
the /sys/conf/
NAME system configuration file to include the
following line:
options QUOTA
2. Edit the /etc/fstab file and change the fourth field of the file
system’s entry to read rw, userquota, and groupquota.
3. Use the quotacheck command to create a quota file where the quota
subsystem stores current allocations and quota limits. Refer to the
quotacheck
(8) reference page for command information.
Administering the UNIX File System 7–25