What is a qtree when using a Network Appliance Filer with IBM® Rational® ClearCase®?
Data on a Network Appliance Filer is organized in volumes. A volume is an independent file system with its own RAID group(s). Every RAID group must contain at least two disks. Each filer must have a root volume to boot (named /vol/vol0).
A qtree is a special subdirectory of the root directory of a volume that gives greater flexibility when storage needs do not demand multiple volumes. Volumes are themselves considered a qtree and can be the target of qtree commands. Therefore, it is recommended to use qtrees from the start.
For more information, refer to the following url, http://www.netapp.com/library/tr/3111.pdf.