I'm ready to buy 2 HDD and I've heard about RAID and since I didn't own 2 HDD before I didn't care to know what it is. But when I did read some guides on it on Tom's I seriously didn't understand the complete use of RAID.
I read the guide and came to the conclusion that RAID should be something like Dual Channel memory , well that’s all I understood about it. Please can some one give a simple logical explanation to what RAID does and if it has any advantages. Help please?
There are raid (redundant array of independent disks )there are various config raid 0 ,1,10 etc. Each having their own advantage like mirror striping making multiple copies of data helping to retrieve data when one of the drives fail. As far as raid 0 is concerned it appears for more than one disks as one which help in access times for data. But defect in any of disks make them unreadable.
So , If I suddenly take one HDD drive away would I screw up my stuff in drives ? 'Cause I’m borrowing one from my friend and I might give it away any time. Once in RAID I shouldn’t remove it?
make sure while raid,there should be not data if it is it will b removed while
doing raid…the most important think in raid ur hdd should be same in capacity,
speed,company
If i have a raid 0 setup i have taken a image copy to a backup drive. consider the case of 1 HDD fail in raid setup, can i re-image the disk as a single sata drive?
Mirroring - Raid 1 (Max performance, but only 160gb)
Striping - Raid 0 (U will get 320GB, but lower performance and u need both disks)
Now in striping if you part data is stored on 1st disk and some part on second disk, but at a bit level.
So Hello will be stored as
DISK1 DISK2
H E
L L
O
Now as u may guess without any one the disks all ur data is useless. But while accessing data because both disks will provide data(incase needed, as in case of example Disk1 will give HEL while Disk2 will give LO at the same time), speed is higher.
Mirroring ovbiously mirrors, thus you get fail-over features and higher performance
RAID is a disk array. In addition to the array modes listed by nitant, which are 2-disk modes, there are other ways to increase array performance and reliability - RAID 5 and 10 are modes that use protection mechanisms in case of drive failure.
A RAID 0 appears as a single drive to the system. When one drive in an array fails or is removed, the array ceases to work. If the disk is replaced, the array needs to be created again, and all previous data is lost. However, a RAID 0 skewed to performance, and RAID 1 towards reliability as opposed to what nitant mentions. A very good RAID 0 array can provide a speed boost of 50% over single drive, or even more depending on the disks and the controllers.
For desktop systems, the processing overhead of a RAID 0 setup obviates any speed benefits. The nature of a desktop systems means multiple fast accesses to small data blocks, whereas a striped array usually boosts performance for sustained read. Write is also slower than a single drive, and Windows writes pretty often to the disk (at least, the system disk) its system state and pagefiles.
Basically, for a home or business PC, it’s not worth it. If you run a database server or a website, RAID is pretty much essential, and there are specialised controllers for it. The ones on your motherboard are useless.
Now that’s informative. Still got 1 doubt lingering in my mind about RAID 1.
You said “Max Performance, but only 160gb” , so that means I get 2 separate drives displayed in Windows and pulling out one drive at any time wouldn’t cause any havoc,right?
In an array, you will always see only one disk, either the capacity of the smallest drive (RAID 1) or the twice the capacity of the smallest drive in the array (RAID 0).
When you pull a drive from a RAID 1 array, the array will show up as defective. It will still work, and will repair itself when you add another drive. Like driving a car with a punctured tyre, or a misfiring cylinder.
A single drive of a RAID 1 array will not be able to boot without the array controller. It’s not like a combination of two disks, it’s a single entity.