Dell EqualLogic PS6210XS EqualLogic Group Manager Administrator s Guide PS Ser - Page 209

NOTE: Dell does not recommend using a combination of local and external authentication where replication and quotas are applied. External Authentication External authentication is managed on a server whenever a user logs in to a container in the same group as the server. Using external authentication, a user can log in to different containers in the group using the same user name and password. This authentication is performed with Active Directory, LDAP, or NIS, for example. When a user logs in to a container using external authentication, the user and group quotas defined for that user and any groups that the user belongs to are applied to that user while logged in to that container. Local Authentication Local authentication is managed directly on a container. With local authentication, the user name and password that a user enters to log in to a container apply only to that container. When a user logs in to a container using local authentication, the user and group quotas defined for that user and any groups that user belongs to are not applied to that user. The quotas for the local user and the primary group for that local user are applied to that user, with the user quota taking precedence over the group quota. About NAS Thin Provisioning Thin provisioning enables you to efficiently allocate storage space, while still meeting application and user storage needs. With a thinprovisioned NAS container, space is created based on actual container data usage, enabling you to "over-provision" NAS cluster storage space (provision more space than what is physically available). When NAS containers are thin-provisioned, NAS cluster storage space is consumed only when data is physically written to the NAS container, not when the NAS container is initially allocated. When data is written to a container, it initially fills or consumes reserved space. When reserved space is exhausted, it begins to consume unreserved space. Thin provisioning offers the flexibility to provision NAS clusters to account for future increases in usage. However, because it is possible for the storage space used by the NAS container to exceed the storage space allocated to the NAS reserve, you should monitor available capacity to ensure that the NAS reserve always has sufficient free space available. You can also specify a portion of the NAS container (reserved space) that is dedicated to the NAS container (no other container can take the space). The total reserved space of all NAS containers cannot exceed the available capacity of the NAS reserve. If a file is deleted from an unreserved portion of a thin-provisioned NAS container, the free space as seen in the NAS cluster increases. The freed-up capacity is also visible and available to clients in the SMB shares or NFS exports. NAS Container Storage Space Terminology The following list defines terminology used in Group Manager related to NAS container storage space. Term Description Size Maximum size of NAS container defined by the storage administrator. Used Space Storage space occupied by writes to the NAS container (user data and snapshots). Reserved Space A portion of a thin-provisioned NAS container that is dedicated to the NAS container (no other container can take the space). The amount of reserved space is specified by the storage administrator. Reserved space is used before unreserved space. Unreserved Space A portion of a thin-provisioned NAS container that is not reserved (other containers can take the space). The amount of unreserved space for a NAS container is the NAS container size minus the reserved space in the NAS container. NAS Container Operations 209