Administrator Guide

Thin and Thick Provisioning for NAS Volumes
In addition to the thin provisioning applied to the NAS pool, NAS volumes can be thin‑provisioned. With thin provisioning (the
default), storage space is consumed on the Storage Centers only when data is physically written to the NAS volume, not when the
NAS volume is initially allocated. Thin provisioning oers the exibility to modify NAS volumes to account for future increases in
usage. However, because it is possible for the storage space used by the NAS volumes to exceed the Storage Center space
allocated to the NAS pool, you must monitor available capacity on the Storage Center(s) to ensure that the
FluidFS cluster always
has sucient free space available. You can also specify a portion of the NAS volume (reserved space) that is dedicated to the NAS
volume (no other volumes can take the space). The total reserved space of all NAS volumes cannot exceed the available capacity of
the NAS pool.
If a le is deleted from a thin-provisioned NAS volume, the free space as seen in Storage Manager increases. The freed-up capacity
is also visible and available to clients in the SMB shares or NFS exports. However, the
Storage Center does not report any capacity
freed up in the NAS pool unless you enable the SCSI Unmap feature.
Thick provisioning allows you to allocate storage space on the Storage Centers statically to a NAS volume (no other volumes can
take the space). Thick provisioning is appropriate if your environment requires guaranteed space for a NAS volume.
Choosing a Strategy for NAS Volume Creation
Choosing to dene multiple NAS volumes enables you to apply dierent management policies, such as data reduction, data
protection, le security style, and quotas, based on your needs.
Consider the following factors to help choose the right strategy based on your environment’s requirements:
• General requirements
– NAS volumes can be created, resized (increased or decreased), or deleted.
– A single NAS volume can contain NFS exports, SMB shares, or a combination of NFS exports and SMB shares.
– The minimum size of a NAS volume is 20 MB (or if the NAS volume has already been used, the minimum size should be more
than the used space or reserved space, whichever is highest.)
• Business requirements: A company or application requirement for separation or for using a single NAS volume must be
considered. NAS volumes can be used to allocate storage for departments on demand, using the threshold mechanism to notify
administrators when they approach the end of their allocated free space.
• Data reduction: Each NAS volume can have a dedicated data reduction policy to best suit the type of data it stores.
• Snapshots: Each NAS volume can have a dedicated snapshot scheduling policy to best protect the type of data it stores.
• Security style: In multiple protocol environments, it might be benecial to separate the data and dene NAS volumes with UNIX
security style for UNIX/Linux-based clients and NTFS security style for Windows-based clients. This separation enables the
administrator to match the security style with business requirements and various data access patterns. The security style can
also be set to Mixed, which supports both POSIX security and Windows ACLs on the same NAS volume.
• Quotas: Dierent quota policies can be applied to dierent NAS volumes, allowing the administrator to focus on managing
quotas when it is appropriate.
• Client subnets: Dierent volumes can be restricted to dierent client subnets.
• Replication schedules: Dierent volumes can have dierent replication schedules and policies.
• Auditing SACL SMB Access: Dierent volumes can have dierent policies for handling Auditing SACL SMB Accesses.
Examples of NAS Volume Creation
The following examples show how NAS volumes can be created to meet the needs of an organization with the departments and
NAS volume requirements described in the following table.
Department
Security Style Snapshots Replication NDMP
Backup
Number of
SMB/NFS
Clients
Read/Write
Mix
Hourly
Change % of
Existing Data
Post
Production
UNIX Hourly No Weekly 20 20/80 1%
Administration
and Finance
NTFS No No Weekly 10 50/50 None
558
FluidFS NAS Volumes, Shares, and Exports