HP StorageWorks Clustered File System 3.6.0 Windows Storage Server Edition Administration Guide (403103-005, January 2008)

Chapter 8: Configure Dynamic Volumes 76
Types of Dynamic Volumes
HP Clustered File System supports two types of dynamic volumes:
striped and concatenated. The volume type determines how data is
written to the volume.
• Striping. When a dynamic volume is created with striping enabled, a
specific amount of data (called the stripe size) is written to each
subdevice in turn. For example, a dynamic volume could include
three subdevices and a stripe size of 64 KB. That amount of data will
be written to the first subdevice, then to the second subdevice, and
then to the third subdevice. This method fills the subdevices at the
same rate and may provide better performance.
• Concatenation. When a dynamic volume is created without striping,
data is written to the first subdevice until it is full. Then data is written
to the second subdevice, and so on.
Dynamic Volume Names
The CFS Volume Manager uses unique device names to control access to
dynamic volumes. These names form the pathnames that servers use to
access shared data.
When you create a dynamic volume, the CFS Volume Manager gives it a
global device name. The name consists of psv followed by an integer. For
example, psv1, psv2, and psv25 are all valid names.
HP Clustered File System stores information about dynamic volumes in a
volume database located on the membership partitions.
Volume Signature
When a dynamic volume is created, a volume signature is written on each
subdevice in the volume. The signature specifies the volume to which the
subdevice belongs.
When a dynamic volume is deported, the subdevices making up the
volume will retain their volume signatures, allowing the volume to be
reassembled when it is imported again.