These days, even business-critical applications are being virtualized, and with the increasing costs and complexity of data environments, it’s not surprising. Some estimate that large organizations are as much as 70% virtualized already, with no plans to go back to physical servers. Virtualization, however, introduces new challenges for the Oracle DBA, including getting visibility to what’s happening in the virtual environment and understanding how that impacts database performance.
In a recent SolarWinds Twitter datachat (#datachat) with George Trujillo (Oracle ACE Director and Master Principal Big Data Specialist at Hortonworks), Charles Kim (Oracle ACE Director and Founder/President at Viscosity North America), Michael Webster (VMware Virtualization and Cloud Solution Architect at Nutanix), Leighton Nelson (Oracle ACE Director and Prinicipal DBA at Sisters of Mercy ), Kai Yu (Oracle ACE Director and Senior Principal Engineer/Architect at Dell ) and Janis Griffin (Senior Sales Engineer at SolarWinds), we explored some of these challenges from the DBA point of view.
Which Oracle databases are getting virtualized and why?
Increasingly, even Tier 1 workloads are being virtualized. Michael Webster notes that especially with VMware vSphere 5.5, there is no longer a technical reason not to virtualize:
In the past few years, Oracle RAC implementations are being virtualized.
While some do fear virtualizing RAC because of the challenges, it can simplify or speed some management tasks like provisioning, upgrades and adding nodes:
Even Hadoop can be virtualized. According to George Trujillo, it’s all about the platform characteristics.
Regardless of which workloads you virtualize, the key is inadequate design and hardware, as Michael Webster observed:
The result of inadequate capacity planning for IO workload, CPU and memory can cause significant performance bottlenecks:
Lack of planning can sometimes even make things worse:
If your database is being virtualized, be sure to work closely with the virtualization managers to ensure your requirements are included.
How is performance tuning different for virtualized database servers?
An Oracle database doesn’t see a difference between running on a virtual machine (VM) or on a physical server, so whatever performance tools a DBA is used to using still work. What is different is that the DBA must now also understand how the virtualization infrastructure impacts the database. According to Janis Griffin, it’s common for DBAs to see virtualization as a black box into which they have no visibility and no way to correlate database performance:
George Trujillo agrees, and believes that DBAs need to develop a deeper understanding of the virtual infrastructure:
To overcome this fear and trepidation, DBAs must develop a good working knowledge of the virtualization infrastructure and how it impacts performance. George Trujillo recommends that DBAs learn as much as they can about the ESXi host and VM configurations:
Finally, it’s a good idea to cultivate an alliance with the virtualization managers. You can learn from them, and they can help you ensure your database runs well in the virtualization environment.
What tools can help me manage virtualized database servers?
Once you understand the virtualization environment, there are tools you can leverage to get insight into the impact on your database. In fact, these tools are critical to effectively managing your virtualized database:
George recommends several tools, including vCenter Operations Manager and Solarwinds Database Performance Analyzer with VM Option. Leighton Nelson adds:
Embrace Oracle database virtualization with no fear
Armed with the knowledge of the virtualization environment and the right tools, the Oracle DBA should be ready to make the most of what virtualization promises while maintaining optimal database performance.
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