User Guide

86 Chapter 5 Managing Clients and Users
If your Xsan computers connect to another Mac OS X Server for user and group
accounts, use Workgroup Manager or Server Preferences to create users and groups as
needed. If existing users and groups aren’t listed when you click the Add button, open
Directory Utility (in /Applications/Utilities/) on your computer and make sure it’s
connected to the correct server for authentication. All computers in the SAN should
use the same directory service.
From the Command Line
You can also set user quotas using the cvadmin quotas set command in Terminal. For
information, see the cvadmin man page or “Viewing or Changing Volume and Storage
Pool Settings (cvadmin)” on page 121.
About Xsan Quotas
Xsan enforces two disk space quotas for each user or group you choose to restrict: a
soft quota and a hard quota. You can set these in combination to establish clear limits
on the amount of storage a user or group can use, while still allowing temporary access
to extra space for unexpected storage needs. You specify quotas individually for each
volume on a SAN. A user who has no quotas specified can use all available space on a
volume.
Soft Quota
The soft quota is the maximum space a user or group is expected to occupy on a
regular basis. It is “soft” because it can be exceeded by an amount up to the hard quota
for a grace period that you specify.
Hard Quota
The hard quota is an absolute limit on the space a user or group can occupy. Users are
prevented from using more space than specified by their hard quotas.
Grace Period
A user or group can exceed the soft quota without penalty as long as each returns
below the soft quota within the grace period you specify.
Soft Quotas Change to Hard Quotas
If a user or group exceeds the soft quota for a time longer than the grace period, the
soft quota is changed to a hard quota. The user or group will not be able to save
additional data on the volume until the user or group members delete enough old files
to bring their usage below the soft quota.