Storage Solutions Please explain RAID

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hash

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Hi,

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?
 
^ Oh, not this . This is was the first thing I did when I wanted to know what it was !

It doesn't explain many question I have about RAID:

1. If I do a RAID 2x160 GB HDD will it appear as a 320 GB in Windows?

2. Does RAID makes my drive access time less ?

3. WHAT does it DO!! Does it make 2 Drives and make it appear 1 in Windows?

4. What's the use?

5. Is making RAID work between two HDD like a ON/OFF switch in BIOS or does it include anything else?
 
1.yes it will appear as a 320 GB in Windows if u raid 2 160gb

2.There ill b increase in average speed as well as burst speed

3.same as 1st

4.It increase the average speed as well as burst speed thats the main point

by this data transfer ill b fast overall performance ill be high....but if u had an error

in 1 da data in other 1 ill also b lost......

5.ya if u off 1 from bios it won't work.....u by ur own have 2 setup da setting from bios

2 make it raid



performance is ultimate u ill enjoy it
 
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?
 
Yes if in raid 0. Because it would be like a file saved across two drives so removing one drive can make the file unreadable.
 
hash said:
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?
Click to expand...
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
 
Because the drive will be converted to a dynamic disk. Later when you add data it will be saved.

he might be saying no data before conversion since conversion also involves formatting.
 
hash said:
No data on both the drives ? wtf :@
Click to expand...

:rofl: :rofl:

Sorry guys .. just cudnt control myself.

i mean, imagined a not so noobie asking a question abt life and being told a bird left u here...

wtf.. that was not the way i started reading stuff..

:rofl:

[i am still lauging... :bleh:]
 
Even i had the same doubt but now its some what cleared. What is the best raid setup in terms of performance and reliability ? Raid 0,1 or 5.

How do you define whether the config should be raid 0,1 and so on.
 
RAID-redundant array of inexpensive disks

vijaycool said:
Even i had the same doubt but now its some what cleared. What is the best raid setup in terms of performance and reliability ? Raid 0,1 or 5.
How do you define whether the config should be raid 0,1 and so on.
Click to expand...

Perfomance - RAID 0
Reliablity/backup-RAID 1

There are other raid setups (0+1) which are commonly used on servers.

To install RAID pres f6 during XP installation/configure bios.
 
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?
 
Ohh for gods sake

You have two basic types of

1) Mirroring - Raid 1 (Max performance, but only 160gb)

2) 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

Code: 
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
 
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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.
 
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You have two basic types of

1) Mirroring - Raid 1 (Max performance, but only 160gb)

2) Striping - Raid 0 (U will get 320GB, but lower performance and u need both disks)
Click to expand...

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?
 
RAID 1 is not highest speed. RAID 0 is.

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.
 
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