Server maintenance is crucial to the server’s overall performance. One of the most significant methods of server maintenance involves utilizing Redundant Array of Inexpensive Disks, more commonly known as RAID. This storage system is fairly standard in most servers and NAS devices, making them a highly useful part of proper maintenance. This is incredibly valuable since data loss can be detrimental to the success of a business.
There are a wide variety of RAID levels—each with their own ideal application and method of fault tolerance. Fault tolerance refers to helping systems minimize data loss by providing a type of ‘safety net.’ They utilize at least two hard disks within their operation. The different RAID levels range from RAID-0 to RAID-10, although the most used levels are 0, 1, 5, 6, and 10.
The system allows for the maintenance of data even when a hard drive fails. For example, when one of the drives in a RAID-5 server fails, an IT professional can simply replace the failed drive and keep all of the data secure.
RAID-5 has become the most common type of RAID level since it allows for efficient, effective, and reliable storage of data. Data striping involves the splitting and distribution of information across multiple drives. Each drive of a RAID-5 configuration utilizes parity, allowing data to be recovered across all drives in the event of a drive failure. Parity acts as a type of fault tolerance within RAID-5 configurations. Data can be rebuilt on a new drive replacement after its previous one has failed.
While RAID-5 systems are incredibly efficient, businesses sometimes opt for servers with a RAID-1 configuration due to its many advantages. RAID-1 utilizes disk mirroring, which involves the use of two disk drives. When a write occurs, a server writes data on both drives rather than just one. When a read occurs, the server chooses to analyze either of the drives for the data. If one drive fails, all of the data can still be accessed by using the other drive. RAID-1 can be implemented in both a hardware and software context. For hardware RAID-1 solutions, two physical drives are used to implement this configuration. For software solutions, a single drive can be split into two storage volumes.
Simple: old is gold
At its core, servers that use a RAID-1 configuration focus on mirroring. RAID-1 is easy to understand since there is no parity or striping involved. Data is simply written on data drives and mirror drives. Instead of striping data across multiple drives and using parity to access any potentially lost data, any and all data that would have been lost can be accessed on either drive. In the event of a drive failure, data does not have to be rebuilt on a new drive using parity; instead, data just has to be copied from one drive onto another replacement drive. Using a RAID-1 configuration is the easiest way to achieve fault tolerance for your data, while RAID-5 utilizes the relatively complex process of data striping and parity to achieve fault tolerance.
Tried and tested
Servers that have used RAID-1 configuration benefit greatly from its simplicity and practicality. The RAID-1 level is tried and tested, serving a number of different businesses across the world. They are also relatively cost-effective.
Read speed benefits over other RAID levels
In addition to its simplicity, the RAID-1 level also offers read speed benefits that other RAID levels cannot provide. These benefits include an exceptional read and write speed, which is partly due to its simplicity. As stated before, systems that utilize RAID-1 level use two sets of drives: data drives and mirror drives. When data is read, the server only reads data from a single drive. This allows for a relatively high read speed that is highly comparable to the performance of reads and writes of a single drive.
While RAID-1 is ideal for applications that require simplistic fault tolerance, it does not mean that a RAID-1 configuration is perfect. There are some disadvantages that come with choosing RAID-1 level for your server system.
Double the storage
One of the biggest drawbacks of this RAID level is its storage. When buying drives, you would need to purchase double the amount. For example, if you invest in a storage unit that has two terabytes of memory, then you would only be able to use one terabyte. This is due to how the configuration works; there needs to be at least two drives in a RAID-1 configuration. One needs to be used as a data drive while the other is used as a mirror drive. So, when purchasing a disk drive for your server, you need to consider the fact that your server will only be able to use half of the memory that you pay for.
No hot swapping
With regard to using a software RAID-1 solution over others, a drawback of using this configuration is its inability to allow for the hot swapping of drives. The term refers to the replacement of a hard drive and other computer or server components while the system remains operational. While some configurations allow for hot swapping, many do not. When a drive is fried or breaks down, it can only be replaced after the server or system has been fully powered down. This is incredibly inefficient since shutting down a server means that it will be inaccessible for a period of time, and depending on the nature and use of the server, this could seriously affect its users and the business.
Using a RAID-1 configuration for your server has its benefits but it also does have a number of disadvantages. The main benefit that this type of configuration offers is its simplicity, its read speed, and its relative cost-effectiveness. Using mirror drives to accompany its data drives, the RAID-1 level allows for a simplistic way of achieving fault tolerance.
However, some software RAID-1 solutions require the total shutdown of a server in order to physically replace the drive rather than performing a hot swap. The use of a RAID-1 level configuration also requires double the storage since its capacity is half of a single drive or the smallest size out of a pair of drives. Still, the RAID-1 configuration is an effective fault tolerance solution despite these disadvantages.