RAID-Z vs RAID-10 for Hosting: Which Setup Delivers Better Performance Under Load?

Have you ever noticed your server lagging and thought, “What is happening now?” I have had this experience too. When a website or app has been heavily trafficked, storage is when storage reveals itself to be a real powerhouse. It is often during this time you are faced with this question: Is RAID-Z better or is RAID-10 better when it gets busy?

Let’s keep it simple and talk as friends would.

Why a Lot of People Choose RAID-10​

I call RAID-10 the “fast and safe” alternative. It provides fast reads, fast writes, and solid protection in the event of a drive failure.

Some benefits of using RAID-10:

• It provides low latency, even during traffic a spike.
• It provides high IOPS, which allows a database to run fast.
• It has an easy rebuild when a drive dies.
• It remains consistent and smooth during heavy loads.

During my use of RAID-10 in a busy MySQL server, there was never a lag during the spike. It felt solid throughout the entire process.

Pros of RAID-Z (and Challenges)​

RAID-Z, which is used with ZFS, focuses on space-efficient storage, and data protection. It leverages advanced features such as checksums, snapshots, and compression.

The benefits of using RAID-Z include:

• Space efficiency
• Very good data protection
• Excellent performance for large files
• ZFS features which might be useful

That sounds fantastic, right? It is, until the workload is heavily loaded with many small read/write requests.

From my experience, when I started hammering RAID-Z with a lot of small database requests, it started to drag and almost seemed to say, "Could you slow down a little."

Which One is Better Under Load?​

Let’s not dance around the question - you want the answer:

• RAID-10 will outperform RAID-Z when the server experiences load.
• RAID-Z is certainly capable and serves its purpose, but not on continuous, random workloads.
• RAID-10 maintains lower latency and fast serving speeds for sites and applications.
• RAID-Z will exhibit more latency under load because while performing, it is also calculating parity.

So, if your site may be leveraging databases, e-commerce, apps, or has a constant read/write cycle, RAID-10 wins hands down.