Setting up a Synology SSD cache to speed up file access

What SSD Cache Does for a Synology NAS

As data access patterns get more complicated, regular hard drives may not be able to keep up with requests for files, metadata operations, and workloads from multiple users. SSD cache on a Synology NAS is meant to fill this gap by speeding up read and write operations, giving you faster access to files without having to replace high-capacity HDD storage.

SSD caching can make Synology NAS file sharing, backups, collaboration tools, and hybrid workloads much faster without raising costs for businesses that use it for these things.

What is the SSD Cache on a Synology NAS?

SSD cache uses solid-state drives to hold data that is accessed often for a short time. When enabled, the NAS serves files or metadata that are often requested from SSDs instead of spinning disks. This lowers latency and speeds up performance overall.

Synology supports:

SSD cache that can only be read, which speeds up file access
Read-write SSD cache, which speeds up both reading and writing

The right type of cache depends on the workload and the need to protect data.

When SSD Cache Really Matters

SSD cache works best in places with:

A lot of little files
Random read operations that happen often
Several people accessing shared folders at the same time
Synology Drive and other active collaboration platforms
Workloads that look like databases or virtual machines

SSD cache doesn’t make a big difference for big sequential transfers like archiving videos or making backups once.

How to Pick the Best SSDs for Cache

Not every SSD works well for NAS caching. Cache SSDs have a lot of write cycles and need to be very durable.

Important things to think about are:

SSDs that are enterprise-grade or NAS-certified
High TBW (terabytes written) scores
Protection against power loss when possible
Compatibility of NVMe and SATA depends on the NAS model

Using SSDs that aren’t supported or are made for consumers can cause them to wear out faster and not work as well.

Should you use a read-only or read-write cache?

Cache that can only be read

Read-only cache is easier and safer. It speeds up files that are often accessed without changing the paths for writing.

Best for:

File servers
Media libraries that can be accessed more than once
General work in the office

Data is still safe on HDDs even if an SSD fails.

Cache for Reading and Writing

Read-write cache speeds up both reading and writing, but it also adds some things to think about.

Best for:

Databases
Machines that are virtual
Collaborative spaces with a lot of I/O

Because write data goes through the cache, Synology needs RAID protection on more than one SSD to keep data safe in case a cache drive fails.

How to Set Up SSD Cache in DSM

You can set up the SSD cache through Synology DSM:

Start the Storage Manager.
Go to SSD Cache Advisor to see if the workload is right for you.
Put supported SSDs in the slots that are open.
Make a new SSD cache and choose the type of cache you want.
Give the cache to the right volume or LUN.

The SSD Cache Advisor can help you figure out if caching will help you based on how you actually use your computer.

Effect on performance and realistic expectations

SSD cache makes things better:

Speed of file browsing
Responsiveness of the application
Operations with a lot of metadata
Performance of concurrent access

But it doesn’t take the place of:

Enough RAM
Setting up RAID correctly
Enough bandwidth on the network

SSD cache should be seen as a way to improve performance, not a way to fix hardware that isn’t big enough or network problems.

Workloads for SSD Cache and Backup

You need to plan carefully in environments where backups are common. SSD cache can speed up operations on backup metadata, but big sequential backup jobs may not benefit from cache.

Best practices are:

Setting up backups for times when no one is working
Checking how worn out the SSD is

The availability of the cache does not affect the integrity of backups.

Always put backup reliability ahead of performance improvement.

Keeping an eye on and caring for SSD Cache

Long-term effectiveness requires ongoing monitoring:

Keep an eye on performance metrics and cache hit rates
Keep an eye on the health and lifespan of your SSD
Check how useful the cache is from time to time

You may need to change or remove your cache configuration if access patterns change.

Things You Shouldn’t Do

Using cheap SSDs for consumers
Allowing write cache to work without redundancy
Hoping that cache will speed up slow networks
Not looking at the workload before setting up

Good planning makes sure that SSD cache adds real value instead of making things more complicated.

About the Technology of Epis

Epis Technology offers enterprise IT infrastructure, data protection, and Synology consulting services that help businesses get the most out of their NAS systems in terms of performance and reliability. The company is an expert in setting up Synology, designing storage architectures, optimizing backups, and tuning performance. Epis Technology makes sure that files can be accessed faster while keeping data safe, backups reliable, and the system stable for a long time by looking at workloads and setting up SSD cache correctly.