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A RAID device is a Redundant Array of Independent Disks. The concept was developed in 1987 at UC Berkeley and involves the creation of a virtual disk from multiple small disks in order to deliver improved performance and reliability. There are many flavors of RAID and lots of variations in how to implement it. We detail here a specific instance we use: software RAID1 using IDE disks on a Dell PowerEdge box running Debian "sarge" loaded with grub, managed by mdadm, using the ext3 journaling file system.