Last week I visited the 19th VMUG Belgium meeting. VMUG Belgium is running full conference days since 2 years now, these meetings are very valuable. Erik Schils, VMUG Leader for Belgium always schedules some good presenters.
- When talking about performance baselining: know your workloads. Determine main characteristics like IOPS, MB/s, IO block size, random versus sequential IO and read versus writes.
- Know your applications and look for documentation/common scenario’s.
- Measure your performance using vCenter Graphs or esxtop: IO/s, MB/s, latency, read/write ratio.
- vCenter and esxtop unfortunately don’t provide data on block size and random versus sequential IOs. Use the tool vscsistats for this, it’s part of your ESXi installation. vscsistats is a very powerful tool to determine storage characteristics.
- Important: When starting with a performance baseline, first design business requirements and success criteria.
- Set expectations with regards to drive type (SATA, SAS, FC, SSD). There is a very big difference in characteristics.
- IOmeter is a very good tool that helps in storage performance baselining/troubleshooting. IOmeter can create a single workload on your storage, or coordinate several workloads running on different servers/virtual machines. Eric did a very good and extensive explanation on IOmeter configurations.
- Did you know vCenter Operations Manager can also help you dealing with performance issues? vCenter Operations Manager contains some good data, pretty fine-grained. You can choose to create some custom storage related dashboards using vCenter Operations Manager when using the advanced or enterprise version?
The presentation of Eric de Witte is available on VMUG.COM for download. You need a free account to download, registration here.
Also don’t forget to check Erik Zandboer’s website. Erik Zandboer is colleague of Eric de Witte and has some good content about storage performance on his blog.