3.1.2 Matrix Server Administration Guide

Chapter 6: Configure Dynamic Volumes 73

Types of Dynamic Volumes

Matrix Server supports two types of 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 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 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.

Configuration Limits

The configuration limits for dynamic volumes are as follows:

• A maximum size of 16 TB for a dynamic volume.

• A maximum of 512 dynamic volumes per matrix.

• A maximum of 128 subdevices per dynamic volume.

• Concatenated dynamic volumes can be extended up to 128 times;

however, the total number of subdevices cannot exceed 128.

• Striped dynamic volumes can be extended up to 16 times; however,

the total number of subdevices cannot exceed 128.