When I first built my ESXi server, I thought I’d invest in a good server to allow me to really get my  hands “dirty” with VMware. When it came to acquiring disks, I quickly realise that SSD drives were very expensive … so I ended up with SAS drives.

Didn’t take long to find out it is possible to optimise Memory Resources by using SSD drives. I have therefore decided to invest in two 128 GB SSD drives but never really got the chance to actually put them to test. I connected and used them as local storage.

Recently, prices have come down quite a bit so I thought it’s good time to upgrade my local ESXi local storage. A recent eBuyer deal, came in handy so I managed to get myself two additional 1 TB SSD drives.

Just in case you are wondering why the heck am I not using a NAS, here is the answer: I am actually using a NAS as external storage. Though since I don’t actually have a cluster, I thought my VMs would be running better on local storage. So my NAS is being used as a dump location for VM templates, ISO images, etc.

Furthermore, I was considering running a nested virtual ESXi cluster … so I could potentially have 2-3 virtual ESXi hosts, a virtual NAS, all running on the physical ESXi local storage.

Ok … so back to our topic …

At the moment, my local storage runs on 4 x SSD Sandisk drives and 2 x SAS drives (can’t remember the vendor name):


Before actually doing anything fancy with the SSD disks, I wanted to have a better picture regarding the performance of an SSD vs SAS disk.

How Did I Test?

  1. VM Specs
    1. 1 x vCPU
    2. 1 GB RAM
    3. 2 x vDisks – 25 GB for system partition; 15 GB as testing disk
    4. OS – Windows 2003
  2. Tool used: IOmeter
    1. 4 x workers
    2. all-in-one test
    3. Duration: 20 minutes
  3. Ran the same test three times
    1. VM on 128 GB SSD
    2. VM on 1 TB SSD
    3. VM on 1 TB SAS drive

I think the results below need no further comments:


I don’t know what your reaction is … but I was impressed. Clearly, SSD are indeed much faster. Let me also say that I’ve had the 128 GB SSDs for over a year now and my ESXi server is always on. These disks currently host Cisco and Juniper virtual routers, Linux and Windows VMs, few other open-source virtual appliances … The point is, these disks have been fairly busy and yet, I don’t think they performed too badly in these tests.

As far as I’m concerned, my  next NAS will run with SSD disks! 🙂

Go back to Index

Thank you,
View Rafael A Couto Cabral's profile on LinkedIn

Comments are closed.