# Test the hard drive’s performance

> [HTML Version](disk-performance.html)

When installed to a cluster, the application’s performance and stability depends on the hard drive’s speed. A slow hard drive increases the request latency in the cluster and can cause it to become unstable. We suggest that you use the [fio](https://github.com/axboe/fio) tool to test the hard drive’s speed.

Install and run **fio** to test your hard drive:

````
apt install fio  
mkdir test-data  
fio --rw=write --ioengine=sync --fdatasync=1 --directory=test-data --size=100m --bs=2300 --name=mytest

````
As a result, the \[OBJECT\] parameter in the data section will be equal to the 99.00th percentile. For the storage to be fast enough, the 99.00th percentile must be less than 10 ms. For example, a value of 2000 would mean a delay of 2 ms.  
Please note that the minimum write IOPS must meet the system requirements specified in the [System requirements for BRIX On-Premises](elma365-enterprise-on-premises.md) article.