Harnessing the Power of Storage Virtualization and Site Recovery Manager to Provide HA and DR Capabilities to Business Critical Databases
How do you simplify and improve availability of your Extended distance Oracle Real Application Cluster using vSphere Metro Storage Cluster (vMSC) ?
Storage Virtualization, both host based and appliance based, can pave the way for increased ease of configuration and improved availability of your cluster based applications. vMSC featues including vMotion, HA, DRS and FT as well as extended distance Oracle Real Application Clusters (RAC) are greatly simplified, and in some cases, made possible through the use of storage virtualization technologies such as EMC VPLEX, Netapp Metro Cluster, IBM SVC, HP 3PAR Peer Persistence or Oracle Automatic Storage Management (ASM) disk groups. Continue reading →
Virtual Volumes (VVOLS) a game changer for running Tier 1 Business Critical Databases:
One of the major components released with vSphere 6 this year was the support for Virtual Volumes (VVOLS). VVOLS has been gaining momentum with storage vendors, who are enabling its capabilities in their arrays.
When virtualizing business databases there are many critical concerns that need to be addressed that include:
1. Database Performance to meet strict SLAs
2. Daily Operations e.g. Backup & Recovery to complete in set window
3. Cut down time to Clone / Refresh of Databases from Production
4. Meet different IO characteristics and capabilities based on criticality
5. Never ending debate with DBAs : File Systems v/s Raw Devices , VMFS v/s RDM Continue reading →
One of the relatively newer use cases for SRM is planned migration. With this use case, customers can migrate their business critical workloads to the recovery or cloud provider sites in a planned manner. This could be in planning for an upcoming threat such as a hurricane or other disaster or an actual datacenter migration to a different location or cloud provider.
A protection group is a group of virtual machines that fail over together to the recovery site. Protection groups contain virtual machines whose data has been replicated by array-based replication or by VR. Typically contains virtual machines that are related in some way such as:
A three-tier application (application server, database server, Web server)
Virtual machines whose virtual machine disk files are part of the same datastore group.
The purpose of the exercise was to demonstrate use cases for disaster recovery of real business critical applications (BCA) leveraging VMware solutions such as VMWare Site Recovery Manager (SRM). Techniques to protect against disaster for common business critical applications such as Microsoft Exchange, Microsoft SQL Server, SAP and Oracle Databases are discussed.
What’s the CPU Utilization Of Standalone SAP Central Services in a Virtual Machine?
Since VMware came out with VMware Fault Tolerance (FT) we have considered the deployment option of installing SAP Central Services in a 1 x vCPU virtual machine protected by VMware FT. FT creates a live shadow instance of a virtual machine that is always up-to-date with the primary virtual machine. In the event of a hardware outage, VMware FT automatically triggers failover—ensuring zero downtime and preventing data loss. Central Services is a single-point-of-failure in the SAP architecture that manages transaction locking and messaging across the SAP system and failure of this service results in downtime for the whole system. Hence Central Services is a strong candidate for FT but FT currently only supports 1 x vCPU (vSphere 5.x), so some guidance is required on how many users we can support in this configuration. VMware has given technical previews of multi-vCPU virtual machines protected by FT at VMworld 2013/2014, but now, better late than never, here are the results of a lab test demonstrating the performance of standalone Central Services in a 1 x vCPU virtual machine. Continue reading →
Availability of the applications is one of the important requirements for business critical applications. The vSphere platform provides capabilities to protect against hardware and software failures to meet the stringent SLA requirements of business critical applications.
Virtualized applications can avail of features such as vSphere HA protects from HW failures by restarting virtual machines on surviving hosts if a physical host were to fail. vSphere FT (Fault Tolerance) protects critical servers such as load balancers and other central servers with a small footprint (1vCPU) with zero downtime in the event of HW failures.
vSphere App HA for Application level protection for supported applications. Third party solutions that leverage vSphere Application Awareness API such as Symantec Application HA , NEVERFAIL, etc. layer on top of VMware HA and provide monitoring and availability for most of the common business critical applications.
The type of licensing impacts the cluster design for SAP virtualization. SAP is supported on most common database platforms such as SQL, Oracle, DB2 and SYBASE. When customers procure SAP, they can choose to buy the database licensing through SAP or purchase it directly from the database vendor. This decision impacts the cluster design for virtualized SAP environments.
Let us look at these two scenarios and their impact on the design.
Scenario 1: Database License procured from the DB vendor for SAP:
Database vendors have differing but usually very restrictive policies regarding virtual machines running databases. The cost of licensing databases in the extreme case could force a customer to license for the entire cluster, even though the database could be using only a small subset of the resources. Due to the uncertainty and the risk involved with DB licensing in this situation, it might be prudent to separate the entire database workload into its own cluster. By separating the entire database workload, the physical hardware used for databases can be isolated and licensed fully. Since only database workloads exist in this cluster one can achieve consolidation and efficiency for databases. The main disadvantage is the added overhead of having a separate cluster for databases. Since SAP landscapes have many modules with each module having its own individual database, creating a separate DB cluster with a good number of hosts is worthwhile and justified. Continue reading →
Over the past few years, there has been significant acceleration in adoption of the VMware platform for virtualization of business critical applications. When vSphere 5 was introduced with its initial support for up to 32 vCPU many of the vertical scalability concerns that existed earlier were addressed. This has been increased to 64 processors with the later vSphere 5.x releases ensuring that more than 99% of all workloads will fit vertically.
Having personally worked in IT infrastructure for more than 20 years with a strong focus on implementing and managing business critical applications, I see a general reluctance from application owners to virtualize business critical applications. When virtualizing business applications there are many critical factors one should consider. I seek to address the typical concerns of application owners about Virtualization with this multipart series on Virtualizing BCA. Continue reading →
Recently in partner workshops I have come across some interesting discussions about the impact of hyper-threading and NUMA in sizing business critical applications on VMware. So here is an SAP example based on SAP’s sizing metric “SAPS” (a hardware-independent unit of measurement that equates to SAP OLTP throughput of Sales and Distribution users). The examples here refer to vSphere scheduling concepts in this useful whitepaper The CPU Scheduler in VMware vSphere 5.1 .
SAP sizing requires the SAPS rating of the hardware which for estimation purposes can be obtained from certified SAP benchmarks published at http://www.sap.com/solutions/benchmark/sd2tier.epx . Let’s use certification 2011027 and assume that we plan to deploy on similar hardware as used in this benchmark. This is a virtual benchmark on vSphere 5 with the following result: 25120 SAPS (at ~100% CPU) for 24 vCPUs running on a server with 2 processors, 6 cores per processor and 24 logical CPUs as hyper-threading was enabled. This is a NUMA system where each processor is referred to as a NUMA node. (Note cert 2011027 is an older benchmark, the SAPS values for vSphere on newer servers with faster processors would be different/higher, hence work with the server vendors to utilize the most recent and accurate SAPS ratings). Continue reading →