LDAP integration also makes it easy to manage disk space quotas. You can assign quotas to users, groups, applications, or any combination of the three. Xsan enforces two types of quotas for each user, group, or application:
Soft quota. The soft quota is the maximum space a user or group is expected to occupy on a regular basis. Users can exceed their soft quota, for a specified grace period only, up to their hard quota.
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 quota.
Users or groups can exceed their soft quota provided that they drop below it at some point during the grace period you specify. If users or groups exceed their soft quota for longer than the grace period, the soft quota changes to a hard quota; they will
not be able to save additional data on the volume until they delete old files and drop below the soft quota.