Dell 755 manual Verifying That RAID Is Working, RAID Level, Segment Hard drive

Verifying That RAID Is Working

Your computer displays information pertaining to your RAID configuration at start-up, before loading the operating system. If RAID is not configured, the message none defined appears under RAID Volumes, followed by a list of the physical drives installed in your computer. If a RAID volume is identified, you can then check the Status field to determine the current state of your RAID configuration. The Status field contains information about the following conditions:

•Normal — Your RAID configuration is functioning properly.

•Degraded — One of your hard drives has failed. The computer is still bootable; however, RAID is not functioning and data is not being copied to the other drive.

•Rebuild — Following a degraded condition, the computer has detected the replacement/connection of a secondary hard drive and will automatically restore the RAID configuration the next time the operating system loads.

RAID Level 0

NOTICE: Because a RAID level 0 configuration provides no data redundancy, a failure of one drive results in the loss of all data. To protect your data when using a RAID level 0 configuration, perform regular backups.

RAID level 0 uses a storage technique known as data striping to provide a high data-access rate. Data striping is a method of writing consecutive segments, or stripes, of data sequentially across the physical drive(s) to create a large virtual drive. Data striping allows one of the drives to read data while the other drive is searching for and reading the next block.

serial ATA RAID configured for RAID level 0

segment 1

segment 3

segment 5

hard drive 1

segment 2

segment 4

segment 6

hard drive 2

Another advantage of a RAID level 0 configuration is that it utilizes the full storage capacities of the drives. For example, two 120-GB hard drives combine to provide 240 GB of hard drive space on which to store data.

NOTE: In a RAID level 0 configuration, the size of the configuration is equal to the size of the smallest drive multiplied by the number of drives in the configuration.

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Advanced Features