RAID 5 vs RAID 10: What Type of Protection Do You Need?

In our previous posts, we covered an in-depth overview of what RAID Levels are and we looked at comparisons between RAID 0 & 1, RAID 1 & 5, and RAID 5 & 6 configurations. In these articles you will learn about the advantages and disadvantages of each, as well as, a full comparison of both, and when they are applicable in real life situations. If you’ve already viewed these articles and want to know more about RAID 5 vs RAID 10, then keep on reading.

Quick Recap: What Is RAID?

It stands for redundant array of independent (or inexpensive) disks, which refers to the combination of physical hard drive disks into one virtual unit. There are several different RAID level configurations that you can use, with each offering different advantages, disadvantages, and overall purpose. In this comparison post, we are looking at RAID 5 which uses a parity check system for fault tolerance and RAID 10, which uses mirroring for data redundancy.

What Is RAID 5

RAID 5 is the arrangement of at least three hard disks, with information, and what’s known as parity data, striped across each of them. What this means is that information is broken up into evenly sized chunks and distributed sequentially throughout the array. Parity data is then collected, broken up and distributed as well. This data is what the array will use to calculate and recover any information lost should one of the hard disks fail.

Example

In its minimal setup, a RAID 5 array uses three hard disks and distributes data based on the user’s preference. Let’s say you prefer splitting files in half, and load your array with three, equally sized files labelled “A”, “B” and “C”. Your array would look something like this:

Disk 1Disk 2Disk 3
File A1File A2Parity A
File B1Parity BFile B2
Parity CFile C1File C2

Using this setup, we sacrifice space equal to one hard disk in order to secure the data on every hard disk. As you can see, if any one drive fails, either the files are untouched, or the parity data remains to rebuild what is lost.

Advantages of RAID 5

  • The read speed for RAID 5 is fast.
  • Comes with data redundancy due to parity.
  • The setup is stable.
  • A failed drive can be rebuilt in a timely manner.
  • A good amount of storage space.
  • Drives can be hot-swapped to prevent downtime.
RAID 5 disk setup

Disadvantages of RAID 5

  • All data is lost if two drives fail simultaneously.
  • The parity drive makes write speeds slower.
  • Data restoration can be slow.
  • The setup can be complex for those new to RAID configurations.

What Is RAID 10

RAID 10 is actually a combination of RAID 0 and RAID 1, and also uses disk striping, as well as offers drive security. As opposed to collecting Parity Data, this security is achieved through mirroring, or making an exact replica of each storage drive on separate mirror drives. This means that RAID 10 requires at least 4 drives in order to operate, and additional drives must be added in pairs. The array starts by striping data across the storage drives, then mirrors the data onto the mirror drives, creating pairs of completely identical disks.

Example

As stated, a RAID 10 setup requires at least 4 drives; 2 disks for storage and striping, and 2 for mirroring. Using a typical setup, and a scenario similar to the one above, we would see something similar to the following:

Storage Disk 1Storage Disk 2
File A1File A2
File B1File B2
Mirror Disk 1Mirror Disk 2
File A1File A2
File B1File B2

It quickly shows that no matter how many pairs of disks you have, you will only ever have half the storage. The advantage, however, comes with the fact that a failed drive can quickly be replaced, and the data simply copied from another disk. Additionally, all drives can be accessed at once so a RAID 10 array has almost unparalleled reading speeds.

Advantages of RAID 10

  • Has extremely fast read and write performance since all operations occur in parallel to one another on separate drives.
  • Drives can be hot-swapped to prevent downtime.
  • Can recover extremely fast from a failed state.
  • Has extremely high fault tolerance as it can withstand multiple disks failing.

Disadvantages of RAID 10

  • Is expensive as it has inefficient storage space due to mirroring.

RAID 5 vs RAID 10 Comparison Chart


RAID 5RAID 10
Basic Function/Key FeatureDisk Striping With Parity Check SystemCombines Disk Striping With Mirroring
Storage Disks Required3 or More4
Storage Capacity60-75% or 1 Drive Worth of Space is Lost50%
Parity Check SystemYes – Parity – Single DiskNo Parity Check System
Fault ToleranceYes – 1 Drive Can FailMultiple Drives Can Fail
Data RecoveryYes – Using the Parity Check SystemYes – 100% Redundancy
Overall CostExpensiveVery Expensive
Disk Read PerformanceFairly QuickFantastic Performance
Disk Write PerformanceSlowExcellent Performance
Write Penalty?Yes – Slightly Due to Writing to the Parity BlockNo.
Appropriate PurposeA Balance Between Speed & Data SecurityWhen You Need Fast Read/Write Speeds & Fast Failure Recovery

*Note: storage capacity differs based on how many drives you are using in your RAID configuration.

RAID 5 vs RAID 10 Critical Distinctions

  • RAID 5 uses single parity striping while RAID 10 uses disk striping and mirroring.
  • RAID 5 is cheaper due to a minimum 3 disk setup while RAID 10 uses a minimum 4 and if you add more to a RAID 10, you must add in pairs.
  • RAID 5 has better storage capacity than RAID 10 (1 disk lost versus half).
  • RAID 5 can support a 1-drive failure, while RAID 10 can have up to 3 drives fail in a 4-drive set up. With RAID 10, if you lose all disks in one pair, you lose all data.
  • RAID 10 is better here as it has fast read and write, while RAID 5 only has fast read.

Use Cases: When to Use RAID 5 in Real Life Scenarios

RAID 5 offers a good balance between performance, fault-tolerance, and storage capacity, which makes it good for the following scenarios:

  • If you have a tight budget but still need basic fault-tolerance protection without sacrificing a large amount of storage space or performance.
  • You are running a data archive, application or file server that has large storage capacity requirements.
  • You are running a high-availability solution, such as a news server. Or are a small to medium business that has servers that are limited to 3-16 drives.

Use Cases: When to Use RAID 10 in Real Life Scenarios

RAID 10 is well suited to situations that require all of high fault tolerance, and fast read and write speeds. Such scenarios include I/O intensive applications like:

  • Email servers that require high volumes of data to be collected, moved and saved for later access.
  • Web hosting servers that deal with high amounts of input and output, requiring quick reactions to many users at once.
  • Database implementations that require little to no downtime, as constant access is critical.

Frequently Asked Questions

Why Is RAID 5 Not Recommended Over RAID 10?

RAID 5 is not recommended because it only uses distributed parity and does not have mirroring or redundancy built in. This means that if 1 hard drive disk fails, the entire array is put at risk and data recovery becomes slow and complicated. Beyond this, when compared against RAID 10 which has 100% redundancy, RAID 5 performance is lower.

Is Performance Better in RAID 10 than in RAID 5?

Yes, because it combines the features of RAID levels 0 and 1 which is disk striping and mirroring. RAID 10 optimizes fault tolerance and increases performance by striping volume data across multiple drives in your array.

How Many Hard Drives Do You Need in RAID 5 vs. 10?

For a RAID 5 configuration, you need a minimum of 3 hard drives. For RAID 10, you need a minimum of 4-drives.

Do I Need to Back My Data Up If Using RAID?

While most RAID levels do offer some fault-tolerance, they do not replace regular backups. This is because hard drive failure in any RAID configuration can cause all of your data to be lost. It is always a good idea to use traditional backups if you have critical data.

Wrapping It Up

The biggest key difference between these RAID levels is how they achieve and provide data security. Where RAID 5 collects Parity Data and performs calculations, RAID 10 simply makes an exact duplicate of every inch of data it possesses. This means that RAID 10 can tolerate more drive failures, but will never have more than half of its total storage capacity.

Leave a Comment