Understanding qtrees

What qtrees are

A qtree is a logically defined file system that can exist as a special subdirectory of the root directory within either a traditional volume or a FlexVol volume.

Note
You can have a maximum of 4,995 qtrees on any volume.

When creating qtrees is appropriate

You might create a qtree for either or both of the following reasons:

You can easily create qtrees for managing and partitioning your data within the volume.
You can create a qtree to assign user- or workgroup-based soft or hard usage quotas to limit the amount of storage space that a specified user or group of users can consume on the qtree to which they have access.

Qtrees and volumes comparison

In general, qtrees are similar to volumes. However, they have the following key differences:

Snapshots can be enabled or disabled for individual volumes, but not for individual qtrees.
Qtrees do not support space reservations or space guarantees.

Qtrees, traditional volumes, and FlexVol volumes have other differences and similarities as shown in the following table.

Function	Traditional volume	FlexVol volume	Qtree
Enables organizing user data	Yes	Yes	Yes
Enables grouping users with similar needs	Yes	Yes	Yes
Can assign a security style to determine whether files use UNIX or Windows NT permissions.	Yes	Yes	Yes
Can configure the oplocks setting to determine whether files and directories use CIFS opportunistic locks.	Yes	Yes	Yes
Can be used as units of SnapMirror backup and restore operations	Yes	Yes	Yes
Can be used as units of SnapVault backup and restore operations	No	No	Yes
Easily expandable and shrinkable	No (expandable but not shrinkable)	Yes	Yes
Snapshots	Yes	Yes	No (qtree replication extractable from volume snapshots)
Manage user based quotas	Yes	Yes	Yes
Cloneable	No	Yes	No (but can be part of a FlexClone volume)