Choosing the right RAID for your business
As businesses grow, so does their need for data storage solutions offering superior capacities, performance and reliability.
For many SMEs, the solution to this problem is to utilise RAID arrays.
Such a setup can offer impressive read/write speeds, increased protection
against data loss and capacities that are easily scaled. The benefits of a RAID
differ greatly depending on the way they are setup, however, and this can make
it difficult for decision makers to settle on which RAID arrangement best meets
their business’s needs. As a business that has not only seen substantial growth
within a relatively short period of time but also specialises in data storage
and recovery, Fields Data
Recovery are ideally placed to
provide a comprehensive guide on this matter.
What are RAIDs?
Before we can begin the process of stating which RAID is right for your
business, it’s worth explaining what they are and what they do.
RAID is an abbreviation and stands for ‘Redundant Array of
Independent/Inexpensive Disks’. To put it simply, a RAID array is a type of NAS
(Network Attached Storage) housing at least two – though usually several –
separate pieces of storage media. The way data is written to these pieces of
media is what determines the benefits – and drawbacks – of each setup.
So, without further ado, here are the five most common RAID setups and a
summary of their pros and cons:
RAID 0
This configuration stores data across two or more drives. Known as
‘striping’, the individual bytes that form the data are split across the drives
equally so, if the setup uses four hard drives, exactly a quarter of the
relevant file is stored in each. Think of it like storing a physical 100-page
document across four folders – 25 pages would be stored in each.
Pros
Because data is split across several drives, each needs to read/write a
smaller amount of data resulting in increased speeds. This setup also offers
superior storage capacities.
Cons
RAID 0 offers no protection against data loss. If one drive fails, it is
not possible to access any of the data that’s been stored on the array. As a
result, you’ll either need to accept that the data’s been lost or pay a RAID recovery specialist to recover it
for you.
RAID 1
Like RAID 0, this setup utilises two or more drives. Unlike RAID 0, it
stores all of the bytes that form data to each drive in their entirety (a
process referred to as ‘mirroring’). Say a RAID 1 setup contained three drives,
each one would be an identical copy of the other.
Pros
As data is duplicated across all of the drives in the array, several
backups are effectively created at once thus protecting your organisation from
the negative consequences of data loss. As drives can read ‘portions’ of a file
from each of these locations it’ll also provide better read speeds.
Cons
As data is always being written to each drive in its entirety, this
array offers no improvements on performance when writing data and, as data is
written onto each drive in its entirety, there’s no improvement in capacity.
Also, whilst it provides businesses with a basic backup plan, a RAID 1
setup doesn’t protect against human error or physical damage.
RAID 5
RAID 5 setups use ‘striping’ like a RAID 0 but also use an additional
drive to store ‘parity data’. In laymen’s terms this additional drive can be
used to reconstruct any data lost in the event that one drive fails.
Pros
‘Striping’ offers superior read performance whilst the additional drive
offers a solution in the event of one primary drive failing. This setup also
offers enhanced storage capacity.
Cons
Whilst this setup’s use of ‘striping’ generates superior read speeds,
the need to store parity data every time someone saves a file results in slow
write speeds. The process of recovering data from a parity drive is also
time-consuming.
RAID 6
Like RAID 5, RAID 6 uses a parity drive. Unlike RAID 5, though, it uses
two. By using an additional parity drive, a RAID 6 can rebuild data following
two drives having failed.
Pros
The benefits of a RAID 6 are identical to a RAID 5 with one exception:
this array can be rebuilt even if two drives fail.
Cons
Just like RAID 5, write speeds are slower than you’d expect and
rebuilding a failed array is a slow process.
RAID 10
In order to offer excellent performance and protection, RAID 10 setups
use both ‘striping’ and ‘mirroring’ and is also commonly referred to as RAID
1+0.
Pros
This setup offers great performance and protection against data loss.
Cons
You’ll need at least four drives and, as any data you store will be
duplicated across two, the potential capacity of the array is halved. Storing
large amounts of data in a RAID 10 array can become expensive as a result.
Conclusion
If your budget is large enough, RAID 10 offers both enhanced performance
and reliability. If you only care about performance, a RAID 0 setup will
provide this, whilst RAID 1 suits companies looking for increased reliability.
If a compromise between cost, storage, speed and reliability is required, RAID
5 or 6 are the way to go.
Please remember, however, that a RAID array alone does not provide a comprehensive
backup and data loss plan. These setups should be used alongside more
robust backup such as tape or cloud storage.