Blogs by Ashwin

  To read part 2 please click  here To read part 3 please click  here To read part 4 please click  here   High Availability of SAP Workloads High availability of SAP workloads on azure VMs can be analyzed by two different ways: High availability of SAP workloads consists of- SAP application servers SAP ASCS/SCS instance DBMS server  High availability capabilities of Azure infrastructure includes- Azure VM restart capability (significantly important in single-VM scenarios). High availability of compute (VMs), network, and storage, based on availability sets and zones. Note- As these two context compliments each other, then you should design by combining the benefits of both of them.  Failover Clustering A failover cluster is known as a group of independent servers that works together to increase the availability of applications as well as services, and if a node failure occurs, it can perform node arbitration which will transfer the workload to one of t...

  Ultra Disk A new Azure storage type called Azure Ultra Disk will be soon introduced by Microsoft whose capabilities are not bound to the disk size anymore and you can define these capabilities as follows: Size of a disk ranging from 4 GiB to 65,536 GiB IOPS range from 100 IOPS  to 160K IOPS (maximum depends on the VM types as well) Storage throughput from 300 MB/sec to 2000 MB/sec  It allows you to define a single disk that fulfills your size, IOPS, as well as disk throughput range while running a configuration mix between Ultra disk and Premium Storage which also results in limiting the usage of Ultra Disk to the performance critical /hana/data as well as /hana/log volumes while covering the other volumes with Azure Premium Storage. It also offers better read latency as compared to Premium Storage which is advantageous when you want to reduce the HANA startup time and the subsequent load of the data into memory.  Production recommended storage solution with pure U...

  SAP HANA Azure VM Storage Configurations Azure offers different SAP HANA certified Azure Storage types for SAP HANA deployments such as Azure Premium SSD, Ultra Disk, and  Azure NetApp Files while also providing two deployment methods for VHDs on Azure Standard and Premium Storage. The minimum requirement of SAP HANA certified for different storage types are as follows: Azure Premium SSD- /hana/log can be cached with Azure Write Accelerator whereas /hana/data volume can be placed on Premium SSD without Azure Write Accelerator or on Ultra Disk. vAzure Ultra disk at least for the /hana/log volume- It can be palced on either Premium SSD without Azure Write Accelerator or in order to get faster restart times Ultra Disk. NFS v4.1- Volumes on top of Azure NetApp Files for /hana/log and /hana/data. In an on-premises world you rarely care about I/O subsystems and its capabilities because the appliance vendor has to make sure that the minimum storage requirements are met for SAP HANA...

  To read part 1 please click  here To read part 2 please click  here To read part 3 please click  here To read part 4 please click  here SQL Server 2014 Buffer Pool Extension It introduced a new feature which is called Buffer Pool Extension whose functionality extends the buffer pool of SQL Server, which is kept in memory with a second-level cache that is backed by local SSDs of a server or VM. If we compare Buffer Pool Extension to Azure Premium Storage Read Cache, no significant advantages are expected for Buffer Pool Extensions, as recommended for (SQL Server data files) because both caches are using the local disks of the Azure compute node. SQL Server Buffer Pool Extension's experiences with SAP workloads is mixed an does not give any clear recommendation on whether to use it on all cases. Hence, its usage is limited to some rare cases and should not be a mainstream case. Oracle According the SAP installation manual, Oracle-related files shouldn't be insta...

  To read part 1 please click  here To read part 2 please click  here To read part 3 please click  here To read part 5 please click  here Ultra SSD A new Azure Storage type called Azure Ultra SSD is in the process of introduction by Microsoft and its disk capabilities are not bound to the disk size which mainly differentiate it from Azure Storage. You can also define the following capabilities for Ultra SSD: Size of a disk ranging from 4 GiB to 65,536 GiB IOPS range from 100 IOPS to 160K IOPS (maximum depends on the VM SKU) Storage throughput from 300 MB/sec to 2,000 MB/sec  You have an option of attaching both UltraSSD and Premium Storage disks to the same Azure VMs which helps you to restrict the usage of UltraSSD for the performance critical/hana/data and /hana/log/volumes as well as implement other volumes with Premium Storage. SAP HANA Dynamic Tiering 2.0 It provides the ability to offload less frequently access data from memory into extended storage, ...

  To read part 1 please click  here To read part 2 please click  here To read part 4 please click  here To read part 5 please click  here Azure VM Storage Considerations While planning your disk layout you can find optimal configuration with the help of following factors: The number of data files The number of disks that contain the files The IOPS quotas of a single disk The data throughput per disk The number of additional data disks possible per VM size The number of storage throughput a VM can provide The latency difference an Azure Storage type can provide VM SLAs Paging/Swap Files While configuring the paging/swap files you should use the following recommendations: Windows operating system pagefile should reside on the D: drive (i.e. non-persistent disk) Linux swapfile should reside under/mnt/resource and can be configured in the configuration file of the Linux Agent/etc/waagent.conf; you can also add or change the following settings- ResourceDisk.EnableSwa...

  To read part 1 please click  here To read part 3 please click  here To read part 4 please click  here To read part 5 please click  here Load Balancing The load balancer uses probe ports to determine as well as route the traffic to an active DBMS node, but of there's any failover then the most common SAP application architecture can automatically reconnect against the private virtual IP address without the need for the SAP application to reconfigure it, while the load balancer redirect the traffic against the private virtual IP address without any need for the SAP application to reconfigure. The loaf balancer also offers an option of DirectServerReturn which if configured, can help in directing the traffic from the DBMS VM to the SAP application layer directly to the application layer without routing through the load balancer. But, if it isn't configured, then the return traffic to the SAP application layer is routed through the load balancer. You can also use ...

  To read part 2 please click  here To read part 3 please click  here To read part 4 please click  here To read part 5 please click  here Azure VM Compute Considerations The major criteria for determining if a VM size offers throughput requirement needed for the given SAP workload is constituted by the SAPS metric which also represents one of the primary factors considered by Microsoft and SAP while certifying Azure VMs for SAP NetWeaver as well as SAP HANA. Hyperthreading on bare-metal server can improve the overall throughput but , the increase is not directly proportional to to the number of CPU threads of the host which results in the delivery of 130-140% of the throughput more by a single core with two hyperthreaded CPU threads in comparision to the same processor core without hyperthreading. D(S)v3, E(S)v3, M-series are some of the NetWeaver and/or SAP HANA certified Azure VM families running on Intel Hyperthreading enabled  host hardware. It is recom...

  High-Level Architecture The overall architecture of SAP HANA on Azure (Large Instances) readily offers ability and flexibility of Azure to scale resources for the SAP application layer to meet your needs. The Azure Large Instance stamp composed of the following resources: Compute- Servers that are based on one of the several generations of  Intel Xeon processors that provide the necessary compute capability and are SAP HANA certified. Network- A unified high-speed network fabric that interconnects the compute and storage. Storage- It can be easily accessed through a unified network fabric and its storage capacity depends upon the specific SAP HANA on Azure (Large Instances) configuration specified by each customer but more storage capacity can be added at an additional monthly. SAP HANA on Azure (Large Instance) are offered in multiple Azure regions which facilitates the disaster recovery capabilities that customers can easily choose to implement as different Large Instance ...

  High Level Architecture The following reference architecture shows a set of proven practices for running S/4 HANA in a high availability environment that supports disaster recovery on Azure. Architectural Components This reference architecture provides details about an enterprise-grade, production-level system and this configuration can also be reduced to a single virtual machine to suit your business, but the following components are needed: Virtual Network-   The Azure virtual network service can connect all the Azure resources with each other securely while also allowing you to connect to an on-premises environment via virtual gateway provisioned as a part of ExpressRoute or Site-to-Site connection. This virtual gateway resides in the virtual network that serves as the hub of a hub-spoke hierarchy consisting of multiple, peered virtual networks while the spokes represent the individual virtual networks hosting the SAP applications and database tiers. Subnets- All the...

  SAP NetWeaver with AnyDB on Azure VMs This reference architecture consists of a set of proven practices for running SAP NetWeaver in a Windows environment on Azure with high availability and is always deployed with specific VM sizes that can changed to accommodate your organization's needs accordingly. High level architecture Architectural components The architecture exhibits the following infrastructure and key software components: Virtual network- The Azure Virtual network can securely connect all the Azure resources to each other as well as an on-premises environment via virtual gateway provisioned as a part of ExpressRoute or Site-to-Site connection. An ideal VDC design allows the virtual gateway to reside in the virtual network that also serves as the hub of a hub-spoke hierarchy containing multiple, peered virtual networks. The spokes represents the individual virtual networks hosting the SAP applications and database tiers. Subnets- Every virtual network is divided into se...

  Overview According to the Microsoft Azure Support Prerequisites, you must enable built-in SAP monitors about configuration as well as resource utilization from the underlying Azure infrastructure for full support. Hence, all the Azure instances that hosts software and related DBMS systems must be set up as follows: The Azure Monitoring Extension for SAP is deployed and correctly configured. Data from the Azure Monitoring Extension for SAP is visible in the SAP NetWeaver system.  The following technical requirement should be available for use of the Azure Monitoring Extension for SAP: An active route to the internet is required by the Azure Virtual Machine instance to easily access the Azure Extension Pool which also need the setting up of Internet proxies for the Virtual Machine Instance before deploying the Azure Virtual Machine Extension for SAP. The SAP Enhanced Monitoring is deployed which consists of the enhanced SAP Host Agent and monitors transaction of ST06 to precis...

  The following high availability provisions are applicable to Azure VM-based deployments: Window Server- Microsoft supports Windows Server Failover Cluster in Azure VMs with replication for non-shared storage. While SAP does not tests its applications with replication for non-shared storage, Microsoft can easily guarantee full transparency of this technology for SAP applications. Hence, the SAP applications can be operated by following the guidelines on how to set up HA configurations for SAP NetWeaver applications on Azure.  SUSE Linux Enterprise Server for SAP Applications- SUSE and Microsoft supports the SUSE Linux Enterprise Server for SAP Applications based cluster for HANA System Replication and SAP NetWeaver ASCS.  Red Hat Enterprise Linux HA Add-on- Red Hat and Microsoft supports the Red Hat Enterprise Linux HA Add-on for HANA System Replication and SAP NetWeaver ASCS.     Regarding SAP HANA on Azure (Large Instances), Microsoft supports some ...

  Network Security It is required for any SAP production system installed on Azure to operate in Virtual Private Network(s) which is/are connected to your datacenters with Azure site-to-site or ExpressRoute connectivity. End-user access to the application should be routed through your company's intranet and the Azure's site-to-site or ExpressRoute connections to the applications hosted in Azure VM Services. This way, the network and other security policies defined for on-premises applications are extended to the application in the Azure VMs. A design that is NOT supported is the segregation of the SAP application and DBMS layers into different Azure VMs that are not peered with each other. It is recommended to segregate the SAP application and DBMS layers by using subnets within an Azure virtual network instead of using the different Azure virtual networks. But, if you segregate the two layers into the different virtual networks, the two virtual networks need to be peered. The ...

  Azure VM NFS Storage Azure VM NFS storage is widely available for SAP workloads can be easily implemented by using Distributed Replicated Block Device (DRBD) with the help of Pacemaker clustering on Azure VMs running SUSE and also by using GlusterFS clustering on RHEL. Managed NFS storage is available in the form of Azure NetApp Files which is an enterprise-class, high-performance, metered file storage service. Azure NetApp Files supports a wide range of workloads and is highly available by default. Snapshots set up and service as well as performance level can be selected through the service. Microsoft has already tested the SAP file shares with Azure NetApp Files for application-level high availability and plans to provide support for SAP HANA in the near future, after the Azure NetApp Files are certified by SAP. Azure VM SMB Storage SMB shares are highly available for SAP workloads in Azure VMs and can be readily implemented by using Storage Space Direct (S2D)-based clusters wi...

  Azure VMs SAP certified operating systems supported for SAP products on Azure VMs includes: Microsoft Windows Server 2008 R2, 2012 (R2), 2016 and 2019 SUSE Linux Enterprise Server 12 (SLES 12) and higher SUSE SLES for SAP Applications (based on SLES 12) and higher Red Hat Enterprise Linux 7 (RHEL 7) and higher Red Hat RHEL for SAP (based on RHEL 7) and higher Red Hat RHEL for SAP HANA (based on RHEL 7) and higher Oracle Linux 7 (OL7) While running SAP products on Linux, you should also review the following SAP notes: 2243692- Linux on Microsoft Azure (Iaas) VM SAP license issues 2513384- SUSE Linux Enterprise Server for SAP Applications for Azure 2694118- Red Hat Enterprise Linux HA Add-On on Azure Note- Multi-SID cluster configurations for SAP Central Services is supported with Windows Server as guest operating system on Azure VMs, but it is not supported with any of the Linux distributions. SAP HANA on Azure (Large Instances) SAP-certified operating systems supported for SAP pr...

  General Prerequisites (SAP support in public cloud environments) As we all know, SAP provides scalable, compliant, and enterprise-proven platform for a range of SAP workloads which is based on the criteria stipulated by SAP. The general prerequisites for SAP supports in public cloud environments includes the following: Licensing for SAP software to be deployed. SAP system sizing and knowledge of resource requirements of SAP workloads to be deployed. Certified VM instance sizes and total capacity required by SAP software on the cloud provider platform. Sufficient network connectivity (in regard to bandwidth, latency, and package loss) to the cloud environment that will host SAP workloads. Certified operating systems on which the SAP workloads will be deployed. Support agreement available from the cloud provider. Experience with technical operation of SAP systems and the infrastructure of the cloud provider pertinent to the shared responsibilities model.   Deployment opti...

  Azure Resource Manager Templates Templates are known for providing unique benefits comparing to the traditional deployment methods that rely on the GUI or scripting and programming languages. Similar to the scripts, they can facilitate the deployment of the multicomponent solutions in an automated manner but don't specify the individual steps required to provision these solutions by simply defining their intended end state. All this results in the minimized deployment deployment time and reduces the potential for errors.  You can easily deploy the templates multiple times to the same resource group with the same outcome which is useful when you want to recreate an original deployment or remediate any issues resulting from post-deployment changes. Templates also supports VM extensions, allowing you to configure operating systems within Azure VMs as a part of their deployment. These extensions includes configuration management services, such as Power-Shell Desired State Config...