3.6.0 Matrix Server 3.6.0 Administration Guide (5697-7081, December 2007)

Chapter 8: Configure Dynamic Volumes 76

Types of Dynamic Volumes

Matrix Server 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 Matrix 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 Matrix 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.

Matrix Server 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.