Datasheet

13
Technology Overview
Xsan
You can use Xsan administration tools to set user and group permissions, as well as
access privileges, at several levels:
• Restrict user access to folders on a volume by specifying owner, group, and general
access permissions.
• Unmount a SAN volume from selected client computers.
• Restrict a client computer to read-only access to a volume.
• Remove a client from a SAN.
Disk quotas
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.
Quotas are set individually for each volume in a SAN. To establish clear limits, you can
set the soft quota, hard quota, and grace period in combination—while still allowing
temporary access to extra space for unexpected storage needs. Users for whom no
quotas are specified can use all available space on a volume.