Compaq Infortrend manual A logical volume with logical drives of different levels?

logical drive. If a controller fails, the host I/Os originally assigned to the failed controller will be taken over by the existing controller. When the controller fails back (failed controller being replaced by a new one), logical drives will be returned to the replacement controller in its original configuration.

With logical volume - logical volumes can also be assigned to different controllers. The only difference is logical volumes will be used as base units when shifting control during controller failure.

A logical volume with logical drives of different levels?

Multi-level RAID systems

1.RAID (0+1) - this is a standard feature of Infortrend RAID controllers. It brings the benefits of RAID 1 (high availability) and RAID 0 (enhanced I/O performance through striping). Simply choose multiple drives (more than two) to compose a RAID 1 logical drive, RAID (0+1) will be automatically implemented.

2.RAID (3+0) - a logical volume is a multi-level RAID implementation by its own rights. A logical volume is a logical composition which stripes data across several logical drives (the RAID 0 method). A logical volume with several RAID 3 members can be considered as a RAID (3+0), or RAID 53 as defined in "The RAID Book" (from The RAID Advisory Board).

3.RAID (5+0) - a logical volume with several RAID 5 members.

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