ok, are you ready? there are 6 different levels.
RAID level0: striping with no other redundancy. windows nt server supports this, it can stripe data betwenn 2 and 32 disks. only thing is, if one of the disks goes down, you are going to lose a huge chunck of data.
RAID level1: this level is disk mirroring and is normaly used on smaller networks. nt server supports this too. this level has the best data recovery because it is putting an exact image of the data on all drives.
RAID level2: this uses an array of disk striping the data across all disks. this also stores error-correction info that enables it to recustuct a failed disk.
RAID level3: this is the same as level2 but the info is only on one disk in the array. if that disk fails, the array cannot rebuild its contents.
RAID level4: same as level2 but with the ability to perform a checksum verification. the checksum is a sum of bits in a file. forgto to mension that levels 2,3,4 are not supported by NT.
RAID level5: this has everything but the mirroring. and NT does support this. it is the most widely used. usualy called stirp sets with parity. with this installed you can use hot swap drives and can change bad drives without shutting them down. this requires at least 3 disks to work.
i hope this helps with your decision. RAID is very good for keep track of data. i don't know much about legato products.
