Users Guide
Data stored on a single disk can be considered a simple volume. This disk could also be defined as a virtual disk that comprises only a single physical disk.
Data that spans more than one physical disk can be considered a spanned volume. Multiple concatenated disks can also be defined as a virtual disk that
comprises more than one physical disk.
A dynamic volume that spans to separate areas of the same disk is also considered concatenated.
When a physical disk in a concatenated or spanned volume fails, the entire volume becomes unavailable. Because the data is not redundant, it cannot be
restored by rebuilding from a mirrored disk or parity information. Restoring from a backup is the only option.
Because concatenated volumes do not use disk space to maintain redundant data, they are more cost-efficient than volumes that use mirrors or parity
information. A concatenated volume may be a good choice for data that is temporary, easily reproduced, or that does not justify the cost of data redundancy.
In addition, a concatenated volume can easily be expanded by adding an additional physical disk.
Figure 3-1. Concatenating Disks
l Concatenates n disks as one large virtual disk with a capacity of n disks.
l Data fills up the first disk before it is written to the second disk.
l No redundancy data is kept. When a disk fails, the large virtual disk fails.
l No performance gain.
l No redundancy.
Related Information:
See the following:
l "Organizing Data Storage for Availability and Performance"
l "Controller-supported RAID Levels"
l "Number of Physical Disks per Virtual Disk"
l "Maximum Number of Virtual Disks per Controller"
RAID Level 0 (Striping)
RAID 0 uses data striping, which is writing data in equal-sized segments across the physical disks. RAID 0 does not provide data redundancy.
Figure 3-2. Striping Disks