IBM Db2 Azure Virtual Machines DBMS deployment for SAP workload

With Microsoft Azure, you can migrate your existing SAP application running on IBM Db2 for Linux, UNIX, and Windows (LUW) to Azure virtual machines. With SAP on IBM Db2 for LUW, administrators and developers can still use the same development and administration tools, which are available on-premises. General information about running SAP Business Suite on IBM Db2 for LUW is available via the SAP Community Network (SCN) in SAP on IBM Db2 for Linux, UNIX, and Windows.

For more information and updates about SAP on Db2 for LUW on Azure, see SAP Note 2233094.

Various articles on SAP workload on Azure have been published. We recommend beginning with Get started with SAP on Azure VMs and then read about other areas of interest.

The following SAP Notes are related to SAP on Azure regarding the area covered in this document:

Note number Title
1928533 SAP Applications on Azure: Supported Products and Azure VM types
2015553 SAP on Microsoft Azure: Support Prerequisites
1999351 Troubleshooting Enhanced Azure Monitoring for SAP
2178632 Key Monitoring Metrics for SAP on Microsoft Azure
1409604 Virtualization on Windows: Enhanced Monitoring
2191498 SAP on Linux with Azure: Enhanced Monitoring
2233094 DB6: SAP Applications on Azure Using IBM DB2 for Linux, UNIX, and Windows - Additional Information
2243692 Linux on Microsoft Azure (IaaS) VM: SAP license issues
1984787 SUSE LINUX Enterprise Server 12: Installation notes
2002167 Red Hat Enterprise Linux 7.x: Installation and Upgrade
1597355 Swap-space recommendation for Linux

As a pre-read to this document, you should have read the document Considerations for Azure Virtual Machines DBMS deployment for SAP workload plus other guides in the SAP workload on Azure documentation.

IBM Db2 for Linux, UNIX, and Windows Version Support

SAP on IBM Db2 for LUW on Microsoft Azure Virtual Machine Services is supported as of Db2 version 10.5.

For information about supported SAP products and Azure VM types, refer to SAP Note 1928533.

IBM Db2 for Linux, UNIX, and Windows Configuration Guidelines for SAP Installations in Azure VMs

Storage Configuration

For an overview of Azure storage types for SAP workload, consult the article Azure Storage types for SAP workload All database files must be stored on mounted disks of Azure block storage (Windows: NTFS, Linux: xfs or ext3). Remote shared volumes like the Azure services in the listed scenarios are NOT supported for Db2 database files:

Remote shared volumes like the Azure services in the listed scenarios are supported for Db2 database files:

  • Hosting Linux guest OS based Db2 data and log files on NFS shares hosted on Azure NetApp Files is supported!

Using disks based on Azure Page BLOB Storage or Managed Disks, the statements made in Considerations for Azure Virtual Machines DBMS deployment for SAP workload apply to deployments with the Db2 DBMS as well.

As explained earlier in the general part of the document, quotas on IOPS throughput for Azure disks exist. The exact quotas are depending on the VM type used. A list of VM types with their quotas can be found here (Linux) and here (Windows).

As long as the current IOPS quota per disk is sufficient, it is possible to store all the database files on one single mounted disk. Whereas you always should separate the data files and transaction log files on different disks/VHDs.

For performance considerations, also refer to chapter 'Data Safety and Performance Considerations for Database Directories' in SAP installation guides.

Alternatively, you can use Windows Storage Pools (only available in Windows Server 2012 and higher) as described Considerations for Azure Virtual Machines DBMS deployment for SAP workload or LVM or mdadm on Linux to create one large logical device over multiple disks.

For Azure M-Series VM, the latency writing into the transaction logs can be reduced by factors, compared to Azure Premium storage performance, when using Azure Write Accelerator. Therefore, you should deploy Azure Write Accelerator for the VHD(s) that form the volume for the Db2 transaction logs. Details can be read in the document Write Accelerator.

IBM Db2 LUW 11.5 released support for 4-KB sector size. Though you need to enable the usage of 4-KB sector size with 11.5 by the configurations setting of db2set DB2_4K_DEVICE_SUPPORT=ON as documented in:

For older Db2 versions, a 512-Byte sector size must be used. Premium SSD disks are 4-KB native and have 512-Byte emulation. Ultra disk uses 4-KB sector size by default. You can enable 512-Byte sector size during creation of Ultra disk. Details are available Using Azure ultra disks. This 512-Byte sector size is a prerequisite for IBM Db2 LUW versions lower than 11.5.

On Windows using Storage pools for Db2 storage paths for log_dir, sapdata and saptmp directories, you must specify a physical disk sector size of 512-Byte. When using Windows Storage Pools, you must create the storage pools manually via command line interface using the parameter -LogicalSectorSizeDefault. For more information, see New-StoragePool.

Recommendation on VM and disk structure for IBM Db2 deployment

IBM Db2 for SAP NetWeaver Applications is supported on any VM type listed in SAP support note 1928533. Recommended VM families for running IBM Db2 database are Esd_v4/Eas_v4/Es_v3 and M/M_v2-series for large multi-terabyte databases. The IBM Db2 transaction log disk write performance can be improved by enabling the M-series Write Accelerator.

Following is a baseline configuration for various sizes and uses of SAP on Db2 deployments from small to large. The list is based on Azure premium storage. However, Azure Ultra disk is fully supported with Db2 as well and can be used as well. Use the values for capacity, burst throughput, and burst IOPS to define the Ultra disk configuration. You can limit the IOPS for the /db2/<SID>/log_dir at around 5000 IOPS.

Extra small SAP system: database size 50 - 200 GB: example Solution Manager

VM Name / Size Db2 mount point Azure Premium Disk # of Disks IOPS Through-
put [MB/s]
Size [GB] Burst IOPS Burst Through-
put [GB]
Stripe size Caching
E4ds_v4 /db2 P6 1 240 50 64 3,500 170
vCPU: 4 /db2/<SID>/sapdata P10 2 1,000 200 256 7,000 340 256
KB
ReadOnly
RAM: 32 GiB /db2/<SID>/saptmp P6 1 240 50 128 3,500 170
/db2/<SID>/log_dir P6 2 480 100 128 7,000 340 64
KB
/db2/<SID>/offline_log_dir P10 1 500 100 128 3,500 170

Small SAP system: database size 200 - 750 GB: small Business Suite

VM Name / Size Db2 mount point Azure Premium Disk # of Disks IOPS Through-
put [MB/s]
Size [GB] Burst IOPS Burst Through-
put [GB]
Stripe size Caching
E16ds_v4 /db2 P6 1 240 50 64 3,500 170
vCPU: 16 /db2/<SID>/sapdata P15 4 4,400 500 1.024 14,000 680 256 KB ReadOnly
RAM: 128 GiB /db2/<SID>/saptmp P6 2 480 100 128 7,000 340 128 KB
/db2/<SID>/log_dir P15 2 2,200 250 512 7,000 340 64
KB
/db2/<SID>/offline_log_dir P10 1 500 100 128 3,500 170

Medium SAP system: database size 500 - 1000 GB: small Business Suite

VM Name / Size Db2 mount point Azure Premium Disk # of Disks IOPS Through-
put [MB/s]
Size [GB] Burst IOPS Burst Through-
put [GB]
Stripe size Caching
E32ds_v4 /db2 P6 1 240 50 64 3,500 170
vCPU: 32 /db2/<SID>/sapdata P30 2 10,000 400 2.048 10,000 400 256 KB ReadOnly
RAM: 256 GiB /db2/<SID>/saptmp P10 2 1,000 200 256 7,000 340 128 KB
/db2/<SID>/log_dir P20 2 4,600 300 1.024 7,000 340 64
KB
/db2/<SID>/offline_log_dir P15 1 1,100 125 256 3,500 170

Large SAP system: database size 750 - 2000 GB: Business Suite

VM Name / Size Db2 mount point Azure Premium Disk # of Disks IOPS Through-
put [MB/s]
Size [GB] Burst IOPS Burst Through-
put [GB]
Stripe size Caching
E64ds_v4 /db2 P6 1 240 50 64 3,500 170
vCPU: 64 /db2/<SID>/sapdata P30 4 20,000 800 4.096 20,000 800 256 KB ReadOnly
RAM: 504 GiB /db2/<SID>/saptmp P15 2 2,200 250 512 7,000 340 128 KB
/db2/<SID>/log_dir P20 4 9,200 600 2.048 14,000 680 64
KB
/db2/<SID>/offline_log_dir P20 1 2,300 150 512 3,500 170

Large multi-terabyte SAP system: database size 2 TB+: Global Business Suite system

VM Name / Size Db2 mount point Azure Premium Disk # of Disks IOPS Through-
put [MB/s]
Size [GB] Burst IOPS Burst Through-
put [GB]
Stripe size Caching
M128s /db2 P10 1 500 100 128 3,500 170
vCPU: 128 /db2/<SID>/sapdata P40 4 30,000 1.000 8.192 30,000 1.000 256 KB ReadOnly
RAM: 2048 GiB /db2/<SID>/saptmp P20 2 4,600 300 1.024 7,000 340 128 KB
/db2/<SID>/log_dir P30 4 20,000 800 4.096 20,000 800 64
KB
Write-
Accelerator
/db2/<SID>/offline_log_dir P30 1 5,000 200 1.024 5,000 200

Using Azure NetApp Files

The usage of NFS v4.1 volumes based on Azure NetApp Files (ANF) is supported with IBM Db2, hosted in Suse or Red Hat Linux guest OS. You should create at least four different volumes that list like:

  • Shared volume for saptmp1, sapmnt, usr_sap, <sid>_home, db2<sid>_home, db2_software
  • One data volume for sapdata1 to sapdatan
  • One log volume for the redo log directory
  • One volume for the log archives and backups

A fifth potential volume could be an ANF volume that you use for more long-term backups that you use to snapshot and store the snapshots in Azure Blob store.

The configuration could look like shown here

Example of Db2 configuration using ANF

The performance tier and the size of the ANF hosted volumes must be chosen based on the performance requirements. However, we recommend taking the Ultra performance level for the data and the log volume. It is not supported to mix block storage and shared storage types for the data and log volume.

As of mount options, mounting those volumes could look like (you need to replace <SID> and <sid> by the SID of your SAP system):

vi /etc/idmapd.conf   
 # Example
 [General]
 Domain = defaultv4iddomain.com
 [Mapping]
 Nobody-User = nobody
 Nobody-Group = nobody

mount -t nfs -o rw,hard,sync,rsize=262144,wsize=262144,sec=sys,vers=4.1,tcp 172.17.10.4:/db2shared /mnt 
mkdir -p /db2/Software /db2/AN1/saptmp /usr/sap/<SID> /sapmnt/<SID> /home/<sid>adm /db2/db2<sid> /db2/<SID>/db2_software
mkdir -p /mnt/Software /mnt/saptmp  /mnt/usr_sap /mnt/sapmnt /mnt/<sid>_home /mnt/db2_software /mnt/db2<sid>
umount /mnt

mount -t nfs -o rw,hard,sync,rsize=262144,wsize=262144,sec=sys,vers=4.1,tcp 172.17.10.4:/db2data /mnt
mkdir -p /db2/AN1/sapdata/sapdata1 /db2/AN1/sapdata/sapdata2 /db2/AN1/sapdata/sapdata3 /db2/AN1/sapdata/sapdata4
mkdir -p /mnt/sapdata1 /mnt/sapdata2 /mnt/sapdata3 /mnt/sapdata4
umount /mnt

mount -t nfs -o rw,hard,sync,rsize=262144,wsize=262144,sec=sys,vers=4.1,tcp 172.17.10.4:/db2log /mnt 
mkdir /db2/AN1/log_dir
mkdir /mnt/log_dir
umount /mnt

mount -t nfs -o rw,hard,sync,rsize=262144,wsize=262144,sec=sys,vers=4.1,tcp 172.17.10.4:/db2backup /mnt
mkdir /db2/AN1/backup
mkdir /mnt/backup
mkdir /db2/AN1/offline_log_dir /db2/AN1/db2dump
mkdir /mnt/offline_log_dir /mnt/db2dump
umount /mnt

Note

The mount option hard and sync are required

Backup/Restore

The backup/restore functionality for IBM Db2 for LUW is supported in the same way as on standard Windows Server Operating Systems and Hyper-V.

Make sure that you have a valid database backup strategy in place.

As in bare-metal deployments, backup/restore performance depends on how many volumes can be read in parallel and what the throughput of those volumes might be. In addition, the CPU consumption used by backup compression may play a significant role on VMs with up to eight CPU threads. Therefore, one can assume:

  • The fewer the number of disks used to store the database devices, the smaller the overall throughput in reading
  • The smaller the number of CPU threads in the VM, the more severe the impact of backup compression
  • The fewer targets (Stripe Directories, disks) to write the backup to, the lower the throughput

To increase the number of targets to write to, two options can be used/combined depending on your needs:

  • Striping the backup target volume over multiple disks to improve the IOPS throughput on that striped volume
  • Using more than one target directory to write the backup to

Note

Db2 on Windows does not support the Windows VSS technology. As a result, the application consistent VM backup of Azure Backup Service can't be leveraged for VMs the Db2 DBMS is deployed in.

High Availability and Disaster Recovery

Linux Pacemaker

Important

For Db2 versions 11.5.6 and higher we highly recommend Integrated solution using Pacemaker from IBM.

Windows Cluster Server

Microsoft Cluster Server (MSCS) is not supported.

Db2 high availability disaster recovery (HADR) is supported. If the virtual machines of the HA configuration have working name resolution, the setup in Azure does not differ from any setup that is done on-premises. It is not recommended to rely on IP resolution only.

Do not use Geo-Replication for the storage accounts that store the database disks. For more information, see the document Considerations for Azure Virtual Machines DBMS deployment for SAP workload.

Accelerated Networking

For Db2 deployments on Windows, it is highly recommended to use the Azure functionality of Accelerated Networking as described in the document Azure Accelerated Networking. Also consider recommendations made in Considerations for Azure Virtual Machines DBMS deployment for SAP workload.

Specifics for Linux deployments

As long as the current IOPS quota per disk is sufficient, it is possible to store all the database files on one single disk. Whereas you always should separate the data files and transaction log files on different disks.

If the IOPS or I/O throughput of a single Azure VHD is not sufficient, you can use LVM (Logical Volume Manager) or MDADM as described in the document Considerations for Azure Virtual Machines DBMS deployment for SAP workload to create one large logical device over multiple disks. For the disks containing the Db2 storage paths for your sapdata and saptmp directories, you must specify a physical disk sector size of 512 KB.

Other

All other general areas like Azure Availability Sets or SAP monitoring apply as described in the document Considerations for Azure Virtual Machines DBMS deployment for SAP workload for deployments of VMs with the IBM Database as well.

Next steps

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