Dell PowerVault NX3500 - Manual (Page 89)

5. Enable or disable the NAS pool unused space alert.
– To enable the NAS pool unused space alert, select the Alert when unused space is over check
box.
– To disable the NAS pool unused space alert, clear the Alert when unused space is over check
box.
6. If the NAS pool unused space alert is enabled, in the Alert when unused space is below size field,
type a size in megabytes (MB), gigabytes (GB), or terabytes (TB) to specify the unused NAS pool space
that triggers an alert.
7. Click OK.
Managing NAS Volumes
A NAS volume is a portion of the NAS pool in which you create CIFS shares and NFS exports to make
storage space available to clients. NAS volumes have specific management policies controlling their
space allocation, data protection, security style, and so on.
You can either create one large NAS volume consuming the entire NAS Pool or divide the NAS pool into
multiple NAS volumes. In either case you can create, resize, or delete these NAS volumes.
NAS volume availability depends on the availability of the MD Array(s). If the MD Array is offline, NAS
volume data is not available for the FluidFS cluster. Correct the MD Array problem to resume NAS volume
availability.
Several NAS features are configured on a per NAS volume basis:
• Quota rules
• Security styles
• Data reduction
• Snapshots
• NDMP backup
• Replication
File Security Styles
The Windows and UNIX/Linux operating systems use different mechanisms for resource access control.
Therefore, you assign each NAS volume a file security style (NTFS, UNIX, or Mixed) that controls the type
of access controls (permission and ownership) for the files and directories that clients create in the NAS
volume.
A NAS volume supports the following security styles:
• UNIX: Controls file access using UNIX permissions. A client can change permissions only by using the
chmod and chown commands on the NFS mount point.
• NTFS: Controls file access by Windows permissions. A client can change the permission and
ownership using the Windows File Properties → Security tab.
• Mixed: Supports both NTFS and UNIX security styles. If you choose this option, the security of a file or
directory is the last one set. Permissions and access rights from one method to another are
automatically translated. For example, if a Windows administrator sets up file access permissions on a
file through a CIFS Share, a Linux user can access the file through NFS and change all the file
permissions. This option is not recommended in production environments, except where there is a
need for scratch space and when you are not concerned about file access security and simply need
some NAS volume space to store files temporarily.
Both NTFS and UNIX security styles allow multi ‐protocol file access. The security style simply determines
the method of storing/managing the file access permissions information within the NAS volume.
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