Factors to Consider When Choosing a RAID Level

Whether it’s a small enterprise or multinational corporation, data is a valuable asset for businesses of all types and sizes. To avoid catastrophic data loss, many businesses rely on RAID. If you also want to ensure data protection by adding RAID to the storage configuration, it’s crucial to choose the right RAID level.

Perhaps you know that there are multiple RAID levels, such as RAID 0, 1, 5, 10, and more. When it comes to setting up RAID, the first step is to choose a suitable RAID level. But with so many options available, it’s easy to get perplexed about which one is exactly appropriate for your business. In this post, we’ll take a look at the factors to consider when choosing a RAID level for a new array. But before we do that, let’s first understand what exactly RAID is and how it works.

What is RAID & How It Works?

RAID (redundant array of independent disks) stores the same data on multiple hard disks or solid-state drives to prevent data loss in an event of drive failure. For the operating system (OS), RAID arrays appear as a single logical drive. The primary purpose of RAID is to provide fault tolerance and improved performance for server machines. This means that if a hard disk fails, the system would continue to operate. RAID works by placing data on multiple disks that increases the mean time between failures (MTBF). This technology utilizes disk mirroring or disk striping techniques. Mirroring helps in copying identical data onto different drives while striping spreads the data over multiple disk drives.

RAID can be hardware-based or software-based. You can set up a Software RAID array without a dedicated hardware RAID controller. For a Hardware-based RAID, you will need to install a dedicated controller in the server. This type of RAID provides better performance than software RAID. The level of performance and fault tolerance you receive from your RAID array depends on the RAID configuration and whether you are using software RAID or hardware RAID controllers.

How to Choose the Right RAID Level?

When choosing a RAID level for a new array, there is no one-size-fits-all approach. There are some crucial factors that you need to take into consideration when making a decision. As you know, there are various RAID levels with different functionalities.

Some RAID levels are best suited for better performance while others provide redundancy. So, you need to consider the specific requirements of your business to choose the right RAID configuration. Let’s take a look at the criteria to be considered when choosing a RAID level.

1.   Performance

Depending on your application needs, you need to choose a RAID level that matches your workload. Different applications on your system have different requirements like some applications are light on I/O needs, while others require faster speed. You need to figure out whether your priority is better performance or data redundancy. For instance, if data loss is not an issue and your main purpose is speed then RAID 0 can work well for you. On the other hand, if you need both performance and reliability, you can opt for RAID 10.

2.   Data Protection

If you want to ensure minimum downtime, then data redundancy is a critical factor for choosing RAID. When picking the RAID level, consider the level of data protection. Not all levels can meet your system availability requirements and ensure less downtime. Even if you maintain consistent data backups, it’s wise to choose RAID that offers data protection. For businesses that store valuable data, it’s better to choose RAID 10 or 60. As compared to RAID 0, the fault-tolerant RAID 10 won’t fail at once if one disk fails. However, no matter which level you choose, there’s always a possibility of data loss. In an event of RAID failure, you will need an expert for RAID data recovery. In addition to this, you should also consider the level of difficulty in RAID rebuilds.

3.   Capacity

Different RAID levels offer different amounts of net usable space. The storage capacity available after accounting for RAID overhead varies from one level to another. So, if usable capacity is your primary concern, you may choose RAID 0 because it provides 100% usable storage of the drives. RAID 0 has no parity information and no mirroring. Unlike RAID 1 or 10 with only 50% capacity, RAID 0 allows full use of all drives.

4.   Cost

Another important factor is the cost of setting up a RAID array. As you know, good things don’t come cheap. If you want superior performance and better capacity, you might have to pay more. When choosing the right RAID level, you need to remember your budget also. For instance, as compared to RAID 0, a highly redundant array such as RAID 10 is more expensive.