RAID is a method of combining multiple disk drives into a single entity in order
to improve the overall performance and reliability of your system. The different
options for combining the disks are referred to as RAID levels. There are several
different levels of RAID available depending on the needs of your system. One
of the options available to you is whether you should use a Hardware RAID solution
or a Software RAID solution.
RAID Hardware is always a disk controller to which you can cable up the disk drives. RAID Software is a set of kernel modules coupled together with management utilities that implement RAID in Software and require no additional hardware.
Pros and cons
Software RAID is more flexible than Hardware RAID. Software RAID is also considerably less expensive. On the other hand, a Software RAID system requires more CPU cycles and power to run well than a comparable Hardware RAID System. Also, because Software RAID operates on a partition by partition basis where a number of individual disk partitions are grouped together as opposed to Hardware RAID systems which generally group together entire disk drives, Software RAID tends be slightly more complicated to run. This is because it has more available configurations and options. An added benefit to the slightly more expensive Hardware RAID solution is that many Hardware RAID systems incorporate features that are specialized for optimizing the performance of your system. For more detailed information on the differences between Software RAID and Hardware RAID you may want to visit: www.adaptec.com
Assess the needs of your system and then decide which RAID solution works best
for you. Please do keep in mind however, that regardless of which RAID solution
you choose, neither can provide against administrator (human) error. Therefore,
frequent, regularly scheduled back ups of your system are highly recommended.