Azure VM disk stress tests for the Temporary Storage (D:\ drive)

To get familiar and know what I have in hands besides the data sheet provided by the Azure documents I have used diskspd to test Azure VM drives.

In this post I share my disk stress tests done for the Temporary Storage you get when you set up a VM in Azure.

In an upcoming post I will be sharing my disk stress tests for the Premium SSD Azure Drives P30, P40 and more... watch out you will be surprised!

I wrap diskspd with a powershell so that all tests are exactly the same and I only modify the block size used by diskspd for the test. I tested with the following 4 different block size: 8k, 64k, 512k and 1024k. For SQL Server typical OLTP workloads 8k and 64k are used and for Data Warehouse the larger block sizes.

The data file size that I have used in these tests with diskspd was 10 GB but when testing with a 1 GB and a 1 TB data file I found no differences and I got the same results.

Each test tests the disk for 4 different type of patterns: Random Reads, Random Writes, Sequential Read and Sequential Writes.

The virtual machine used in these tests is "Standard DS13 v2 (8 vcpus, 56 GiB memory)" on top of "Windows Server 2012 R2 Datacenter" located at Azure East US region.

The graphs below show the test outcome for the 2 key metrics IOps (the number of read and write operations per second) and Throughput (the data transfer rate to and from the storage media in mb per second)

The Azure Temporary Storage is a local SSD drive with Read Only caching enabled which cannot be modified.

These disk stress tests for the Azure Temporary Storage expose a pretty good disk performance and DBAs should consider locating tempdb files on this drive. When reading my next post testing the other Azure Disk types this point will get a more significant meaning.

Azure Temporary Storage

"Every VM contains a temporary disk, which is not a managed disk. The temporary disk provides short-term storage for applications and processes and is intended to only store data such as page or swap files. Data on the temporary disk may be lost during a maintenance event event or when you redeploy a VM. On Azure Linux VMs, the temporary disk is /dev/sdb by default and on Windows VMs the temporary disk is D: by default. During a successful standard reboot of the VM, the data on the temporary disk will persist."

Data sheet provided by the Azure documents

Using a 8k block size

Using a 64k block size

Using a 512k block size

Using a 1024k block size