Qtree management

Meaning of qtree

Qtree information displayed

Security style

Oplocks

This window displays the attributes of all qtrees on the filer and enables you to create qtrees and edit the attributes of qtrees. The Reload button refreshes the display. The Create button creates a new qtree. The Modify button changes the attributes of a selected qtree.

Meaning of qtree

A qtree can be an entire volume or a subset of a volume. It is similar to a partition in that you cannot move files into or out of a qtree. There are, however, two differences between a qtree and a partition:

  • A qtree is more flexible than a partition because you can change the size of a qtree at any time.
  • A qtree enables you to apply attributes, such as oplocks and security style to a subset of files and directories, rather than to an entire volume.

If there are files and directories in a volume that do not belong to any qtrees you create, the filer considers them to be in qtree 0. Qtree 0 can take on the same types of attributes as any other qtrees.

You can create up to 254 qtrees on a filer. You can use qtrees whether or not quotas are enabled on your filer. There are no restrictions on how much disk space can be used by the qtree or how many files can exist in the qtree. To impose these restrictions, use the Disks:Quota Editor window.

To delete a qtree, remove it from a client as you would any directory.

Qtree information displayed

The following list describes the fields displayed in this window:

Volume
The name of the volume in which the qtree resides.
Qtree
The name of the qtree. If the qtree name does not appear for an entry, the information displayed is for qtree 0.
Style
The security style used to determine user access to files and directories within this qtree. It can be one of the following values: unix, ntfs, and mixed. For more information about security style, see Security style.
Oplocks
Indicates whether oplocks (opportunistic locks) are enabled or disabled for the qtree. For more information about oplocks, see Oplocks.

Security style

The following list describes the different types of security styles supported by the filer:

unix
The user's UID and GID, and the UNIX-style permission bits of the file or directory determine user access. The filer uses the same method for determining access for both NFS and CIFS requests. If you change the security style of a qtree or a volume from ntfs to unix, the filer disregards the Windows NT permissions that were established when the qtree or volume used the ntfs security style.
ntfs
For CIFS requests, Windows NT permissions determine user access. For NFS requests, the filer generates and stores a set of UNIX-style permission bits that are at least as restrictive as the Windows NT permissions. The filer grants NFS access only if the UNIX-style permission bits allow the user access. If you change the security style of a qtree or a volume from unix to ntfs, files created before the change do not have Windows NT permissions. For these files, the filer uses only the UNIX-style permission bits to determine access.
mixed
Some files in the qtree or volume have the unix security style, and some have the ntfs security style. A file's security style depends on whether the permission was last set from CIFS or NFS. For example, if a file currently uses the unix security style and a CIFS user sends a set-ACL request to the file, the file's security style is changed to ntfs. If a file currently uses the ntfs security style and an NFS user sends a set-permission request to the file, the file's security style is changed to unix.

By default, the security style of a qtree is the same as that for the root directory of the volume.

Oplocks

By default, oplocks are enabled for each qtree.

If, in the CIFS:Config window, you disable oplocks for the entire filer, oplocks are not sent even if you enable oplocks on a per-qtree basis.

NOTE: When you change the oplock setting for a qtree, existing oplocks are not broken. To break the oplocks after you change the per-qtree oplock setting, you must stop CIFS.