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view volumes and use drives from these volumes for creation of new virtual disks or Online Capacity Expansion

(OCE) of existing virtual disks, provided free space is available. Storage Management allows Rename and Delete

operations on such volumes.

Choosing RAID Levels And Concatenation

You can use RAID or concatenation to control data storage on multiple disks. Each RAID level or concatenation has

different performance and data protection characteristics.

The following topics provide specific information on how each RAID level or concatenation store data as well as their

performance and protection characteristics:

• Concatenation

• RAID Level 0 (Striping)

• RAID Level 1 (Mirroring)

• 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 Reconfiguration 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 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.