Disk Array Types
The RAID disk array types are:
| Type | Description |
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| Software- | The array is managed by software running in a host computer using |
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| Based | the host CPU bandwidth. The disadvantages associated with this |
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| method are the load on the host CPU and the need for different |
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| software for each operating system. |
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| SCSI to SCSI | The array controller resides outside of the host computer and |
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| communicates with the host through a SCSI adapter in the host. |
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| The array management software runs in the controller. It is |
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| transparent to the host and independent of the host operating |
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| system. The disadvantage is the limited data transfer rate of the |
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| SCSI channel between the SCSI adapter and the array controller. |
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| The array controller resides on the bus (for example, a PCI or |
| |
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| EISA bus) in the host computer and has its own CPU to generate |
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| the parity and handle other RAID functions. A |
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| can transfer data at the speed of the host bus (PCI, ISA, EISA, VL- |
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| Bus) but is limited to the bus it is designed for. MegaRAID resides |
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| on a PCI bus, which can handle data transfer at up to 528 MB/s. |
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| With MegaRAID, each channel can handle data transfer rates up to |
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| 160 MB/s per SCSI channel. |
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Enclosure Management
Enclosure management is the intelligent monitoring of the disk subsystem by software and/or hardware.
The disk subsystem can be part of the host computer or separate from it. Enclosure management helps you stay informed of events in the disk subsystem, such as a drive or power supply failure. Enclosure management increases the fault tolerance of the disk subsystem.
14MegaRAID Enterprise 1600 Hardware Guide