Setting Usage Quotas
System Administration Manual
167
Setting Usage Quotas
Disk usage can be controlled and monitored by applying quotas, which can prevent network
users from consuming more disk space (or creating more files) than allowed. Titan supports the
following types of quotas:
•
User and group quotas
. Creating user and group quotas can help monitor and control
disk usage for individual users or groups of users.
•
Virtual Volume quotas
. Creating
Virtual Volumes
can be useful to monitor and control
disk usage on a per-directory basis. With Virtual Volumes, directory tree usage can be
managed independently of users or groups. In addition, user and group quotas can be
created within the Virtual Volume.
Note:
In this section, the terms ‘user’ and ‘group’ are used to indicate NFS
or CIFS users and groups.
Understanding Quotas
Quotas track the number and total size of all files. When these reach specified thresholds,
emails are sent to alert the list of contacts associated with the File System and, optionally,
Quota Threshold Exceeded
events
are logged. Operations that would take the user or group
beyond the configured limit can be disallowed by setting
hard limits
.
Note:
When both Usage and File Count limits are defined, Titan will enforce
whichever is the first quota to be reached.
Quota Thresholds
The configuration settings defining the restrictions a Quota places on the disk usage are called
thresholds, and are described in the following table:
Space Usage
Number of Files
Limit
The total size of all the files should
not exceed this value.
The total number of files should not
exceed this value.
Hard Limit
Titan will block any operation which may cause a Hard Limit to be exceeded. If
a ‘soft’ limit is exceeded, an alert will be issued, but the operation will be
allowed.
Warning
When the total size of all the files
reaches this value, a Warning alert is
issued.
When the total number of files
reaches this value, a Warning alert is
issued.