Example: Logical device configurations

Example 1

The disk group consists of three 1 GB drives. You assign RAID level-0, which uses all the physical drives in the disk group with no redundant or parity storage; then, you type 1000. The logical device will actually only use 999 MB because it is the number closest to and lower than 1000 that is divisible by 3.

Example 2

The disk group consists of three 1 GB drives. You assign RAID level-1E, which provides disk mirroring and stripes data across all physical drives in the disk group. Because the data is mirrored, the capacity of the logical drive is 50% of the physical capacity of the physical drives grouped in the disk group. If you type 1000, the physical capacity used is 2000 MB, twice that of the logical device size. The number that is closest to and lower than 2000 that is divisible by 3 is 1998, which will be the actual space used. The logical drive size is 999 MB, which is 50% of the physical capacity.

Example 3

The disk group consists of three 1 GB drives and you assign RAID level-5 . Data is striped across all three physical drives in the disk group, but the space equivalent to that of one physical drive is used for redundant storage. Therefore, if you type 1000, the number 1000 remains in the Size (MB) field because it is divisible by 2 (drives), which is the space available for data. The physical capacity used is 1500 MB.

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