Users Guide

• RAID Level 5 (Striping With Distributed Parity)
• RAID Level 6 (Striping With Additional Distributed Parity)
• RAID Level 50 (Striping Over RAID 5 Sets)
• RAID Level 60 (Striping Over RAID 6 Sets)
• RAID Level 10 (Striping Over Mirror Sets)
• RAID Level 1-Concatenated (Concatenated Mirror)
• Comparing RAID Level And Concatenation Performance
• No-RAID
Related links
Starting And Target RAID Levels For Virtual Disk Reconguration And Capacity Expansion
Concatenation
In Storage Management, concatenation refers to storing data on either one physical disk or on disk space that spans multiple
physical disks. When spanning more than one disk, concatenation enables the operating system to view multiple physical disks as a
single disk. Data stored on a single disk can be considered a simple volume. This disk could also be dened 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 dened
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-ecient 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.
• Concatenates n disks as one large virtual disk with a capacity of n disks.
• Data lls up the rst disk before it is written to the second disk.
• No redundant data is stored. When a disk fails, the large virtual disk fails.
• No performance gain.
• No redundancy.
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