Guide To RAID Over the last few weeks RAID seems to be comming up over and over the boards so here's a quick rundown: The Basics: RAID = Redundant Array Of Inexpensive Disks So you need 2 or more disks to create a raid array. Ideally the disks must be identical, same size, manufacturer and model. RAID will work with drives of different manufacturers/models/sizes, but the lowest raid performace and size will only be as good as the poorest drive. The Types: SATA RAID is raid using the newer Serial ATA disks, this is common feature on newer motherboards IDE RAID is raid using older Parallel ATA disks (IDE), this is an option on some motherboards or by the use of a PCI raid card SCSI RAID (Unsuprisingly) RAID Using a SCSI controller and disks - Very fast, very reliable and very expensive. The Flavors of RAID: RAID 0 = Striping, 2 or more disks become 1, using a stripe, when data is written it is written accross both disks in a stripe, each disk gets half each, this leads to faster access times as the heads don't have to move as far. The Benifits = Faster Access Times The Problems = If you loose 1 disk you loose the data on both RAID 1 = Mirroring = 2 disks are used in a mirror. The data is written to both disks - they are complete copies of each other The Benifits = Redundancy - If you loose a disk, no problems, the other takes over and no data is lost The Problems = 2X160Gb drives in a mirror = 160Gb space, so can be expensive RAID 5 = Parity and data is striped accross 3 or more drives, you have the speed increase of RAID 0, but the due to the parity bits the array can loose a drive without data loss. The Benifits = Good perfomance, and good redundancy The Problems = Cost - 3+ identical drives and a mid to high end RAID controller are required RAID 4 = Similar to RAID 5, but slower as a drive is used as a dedicated parity drive, which adds a bottleneck RAID 3 = Same as RAID 4, but with a different stripe size JBOD = This is an option on many RAID controllers, it stands for Just A Bunch Of Disks and is a way of having a bunch of different sized disks show up as 1 drive. No performance increase or redundancy is provided. I wouldn't say this is really a RAID array as such There You Go! Hope someone finds this usefull!