Choose RAID for Your Dedicated Server That Aligns with Your Business Needs - 0 views
started by rack bank on 10 Sep 15
started by rack bank on 10 Sep 15
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What RAID set should you select for your dedicated server?
Before coming to this question, it would be imperative to get a little clarity
on what exactly is RAID.
RAID stands for "Redundant Array of Independent Disks".
RAID is a storage technology that links
or combines multiple hard drives so that data can be stored on them as if they
were one logical unit. In other words, RAID takes multiple physical disks and
makes them appear and function as one single drive.
Now, what is a RAID set? RAID set is a secure way to store
data in different schemes or architectures that divide and replicate your data
among various member physical drives within your RAID array. A RAID set
provides important storage characteristics of resiliency, performance, and
capacity. As per standard practices, RAID sets range from RAID 0 to RAID 10.
RAID set is an important question we commonly encounter,
especially for those clients who are moving to their own dedicated server (or
servers) for the first time. Quite common though, also, for clients after they
have suffered a critical data loss from a hardware failure. It is important to
understand the RAID set ranges before picking up one for your dedicated server
or hardware problem mitigation strategy.
So, different RAID sets are discussed as below:
1) RAID 0
RAID 0 involves using 2 or more drives without parity or
mirroring i.e. this RAID set offers no redundancy. If one of the member's
drives fails, data on the drives is lost. Obviously RAID 0 is more of
figurative significance than of application significance. In fact, for each
additional drive that you add to your RAID set, you are mathematically
increasing the probability of huge data loss.
Then, why use RAID 0 at all? Simply to gain operational performance
without the loss of drive capacity!
2) RAID 1
RAID 1 is data that is written to 2 (or more) drives, mirrored
without parity or striping. The member drives in a RAID 1 array essentially
producing a mirror of each other. If one of the member hard drives fails, the
data in the mirror drive is safe. Obviously, no write performance is gained by
the use of 2 member hard drives. In a nutshell, RAID 1 is a simple technology for
additional protection of data for dedicated servers.
3) RAID 2
RAID 2 is bit-level striping that is it splits data at the
bit level then spreads it over a number of member disks. How is the data read? Disk
spindle rotation is synchronized and the data is striped so each sequential
byte is on a different drive. RAID 2 technologies require a minimum of 3 member
drives - one drive to mitigate data loss and other to gain read performance.
The more, the merrier because of the large number of member drives (up to 39!)
that could be accessed in parallel and give high performance. RAID 2 is not
used much these days as the controllers are rare, complex, and expensive.
4) RAID 3
RAID 3 is byte level striping. This time it's not the bits
but data blocks that are subdivided and stored in two or more drives. RAID 3
requires a minimum of three member drives. RAID 3 is one of the commonly chosen
options for managed dedicated
servers as it provides large read and write performance gains,
especially for large file block transfers. RAID 3 is commonly used in video streaming,
publishing and editing. To the flipside advantages, RAID 3 is rather
inefficient with smaller files and I/O operations.
5) RAID 4
RAID 4 is block-level striping, similar to RAID 3, except
that striping is done on a block-level basis rather than a byte level. It has
high read performance as I/O requests are performed in parallel. RAID 4 does
not require the spindles of disk to be synchronized as in RAID 3, thus less
complex and more economical. RAID 4 is not an option especially when it comes
to poor performance of random writing. RAID 4 is not used much in dedicated
servers these days.
6) RAID 5
RAID 5 is block-level striping with important feature of
independent read and writes operational capability (not in parallel like RAID
3). RAID 5 offers accelerated read performance and is considered to be one of
the best all-around systems that combine a high level of security, accelerated
performance, and an extremely efficient use of storage. RAID 5 is one of the
most popular and recommended solutions for most of the server applications and
dedicated server operations.
7) RAID 6
RAID 6 is block-level similar to RAID 5 except that RAID 6
creates two parity blocks for each data block. Thus, a RAID 6 system covers the
chances of data loss better than RAID 5. RAID 6 is suited for scenarios where a
higher degree of reliability or certainty is required. For example: databases, applications, E-mail
and web servers. RAID 6 is expensive option though as it requires a high
availability system.
8) RAID 10
RAID 10 is a combination of RAID 0 and RAID 1, which is a
technology featuring striping of mirror drives. It offers high security by
mirroring all data on a secondary set of disks and parallel processing at the
same time. This system requires a minimum of four member disks. For RAID 10, the
read performance is faster and the storage capacity is less efficient. RAID 10
offers very high performance though it's one of the expensive storage options.
Which
one aligns to my business needs?
This question is not an easy one to answer as it depends on
your current state of business and your velocity of expanding your future
operations. The selection will also depend on your budget (hardware
availability) and at the same time keeping an eye on key goals of performance,
resiliency and storage capacity.