In this simple article I will tell you the magic command how to find out your server’s disk performance (I/O – write and read speed). As per you know, a VPS is just like shared hosting instead it is a shared server. Shortly, vps is multiple servers virtualized in single dedicated server which means you have some neighbors to share the resource with including storage media (HDD/SSD). Disk speed / performance is really crucial and it is one important factor determining overall server speed.
Nowadays there are already many VPS providers offering SSD based virtual servers (to mention: DigitalOcean and RamNode). SSD-powered VPS is actually faster than a VPS powered with traditional HDD. However there is still certain factor that makes performance may vary which is the number of VPSes within that node. In some professional or highend providers, HDD-powered VPS can be as fast as SSD-powered VPS (to mention BuyVM and Linode).
One thing is pretty decent offer, there are also several providers like RamNode that offers the middle solution between SSD and HDD called Cached-SSD. It is a combination of HDD and SSD. All hot data (most frequently accessed) will be stored in SSD while most less accessed data will be stored in HDD.
How to Test Disk Speed (I/O)
Login to your VPS via SSH and issue this magic command;
dd if=/dev/zero of=test bs=64k count=16k conv=fdatasync
How to know how fast your VPS is?
My general rule is: anything over 50 MB/s is considered acceptable. But if you bought a SSD-based VPS and it performs under 100MB/s, then that is unacceptable.
Here’s some results of some Low End VPSes I have:
1. RamNode SSD-Cached 128MB
2. TrueVPS SSD-Cached (now acquired by RamNode)
3. UGVPS (special promo plan) – HDD RAID
4. ServerMania – SSD-Cached
So, what about your server? Go ahead share the result with me 🙂