Performance Tips for ESX

1
Performance Tips for ESX Configuring VMware for
SAP

• Deloitte Consulting SNET
• Larry Rapisarda Technical Architecture

2
Performance Tips for ESX Configuring VMware for
SAP

• These settings apply to both ESX 2.5.x and 3.0.x.
• The SNET is developing a SAP benchmarking
  environment.
• Opportunities for tuning ESX.
• Develop best practices.
• Create sizing and configuration standards for
  supporting various SAP \ ESX architectures.
• Current support for SAP on ESX.
• VMware Announces Support from SAP of VMware ESX
  Server for Production Environments
• SAP will now provide immediate and full support
  to its solutions in 64bit Windows and Linux
  environments running on Vmware ESX.

3
Performance Tips for ESX Configuring VMware for
SAP

• Testing and benchmarking.
• Run benchmarking tests for each application
  environment.
• This gives an understanding of the overhead and
  defines what the expected performance will be for
  each application.
• Benchmarking will also assist in determining the
  SLA each environment is able to meet.

4
Performance Tips for ESX Configuring VMware for
SAP

• Standard hardware for the SNET
• 4 way dual core
• 32 GB RAM
• (2) Qlogic HBA cards
• (2) 72 GB Hard drives
• ESX Filesystem
• / 10GB
• /boot 300MB
• /var/log 2GB
• Swap 2 - 32GB

5
Performance Tips for ESX Configuring VMware for
SAP

• Server Hardware
• HP BL45p
• HP 585
• HP DL380
• IBM x366
• IBM x3650
• Storage
• HP EVA5000
• HP MSA1000
• IBM DS4800
• IBM DS4000
• IBM SVC

6
Performance Tips for ESX Configuring VMware for
SAP

• Boot from SAN
• Functionality is available in ESX for boot from
  SAN
• The suggested configuration is to dedicate 1
  controller to ESX and a separate controller for
  the guest LUNs.
• When booting from SAN we have found
• Contention between VMs and the VMkernel.
• Running a 4 way dual core 32 GB host with about
  15 to 20 guests. The guest VM would experience
  degraded performance due to the vkernel managing
  IO and queuing on the SAN. To the user this
  would look and feel like the network had been
  dropped.

7
Performance Tips for ESX Configuring VMware for
SAP

• Disk Space
• Multi VM LUNs
• Presenting a single LUN to support building
  multiple virtual machines.
• Less management required
• Space is can go un-used.
• Single LUN per VM.
• One LUN formatted as VMFS for each virtual
  machine and its memory.
• Will required additional management.
• Space can be reclaimed.
• LUN Space
• Ensure there is available disk space on each LUN
  being used for each VM.
• When ESX starts its kernel it scans each LUN for
  space. If a VM is in use and its memory makes
  up the free space on the LUN the kernel will
  see this as full and not start correctly.

8
Performance Tips for ESX Configuring VMware for
SAP

• Provisioning LUNs
• Traditionally
• Mass LUN is provisioned.
• A single LUN per guest
• With SAP
• Provision LUNs just like a physical machine.
• A LUN per partition to distribute database files
  over different physical disks. Use at least 2
  VMFS partitions.
• Follow SAP standards

9
Performance Tips for ESX Configuring VMware for
SAP

• Disk Space (cont.)
• ESX host file system.
• Running out of space in any of the mount points
  can cause ESX kernel not to load and VM
  performance issues.
• VMWARE recommends
• /boot 100MB ext3
• / 2560MB ext3
• swap 544MB

10
Performance Tips for ESX Configuring VMware for
SAP

• Resource Pools
• Configuring resource pools can adversely impact
  VM performance.
• Configuring clusters.
• Configuring clusters provides flexibility for
  supporting HA and DRS.
• Configure clusters between multiple blade
  chassis.
• Increases the number of guests you can support in
  a cluster and will protect against a chassis
  and\or blade failure.
• Clusters need available space for failover.
• When configuring a cluster remember you need to
  set your priorities for failover. You want to be
  able to support the entire cluster.

11
Performance Tips for ESX Configuring VMware for
SAP

• Memory
• Insufficient memory in the service console will
  cause poor VI client response.
• Configure enough space for SWAP.
• The swap partition allows ESX Server and
  third-party add-ons to use disk space when more
  memory is needed than the physical RAM allows.
• The minimum value allowed is 100MB.
• Physical Memory.
• When creating virtual machines you have the
  opportunity to over commit the physical memory.

12
Performance Tips for ESX Configuring VMware for
SAP

• Memory with SAP.
• Do not commit more memory than is physically
  available on the host.
• Use the memory reservation to commit the full
  amount you have provisioned to each vm.

13
Performance Tips for ESX Configuring VMware for
SAP

• vCPU \ CPU
• Use the latest processor available.
• This will give you greater support for virtual
  infrastructure.
• Virtual machines should be configured with the
  least number of vCPUs.
• Increased load balancing
• More flexibility
• vCPU \ CPU with SAP
• Do not over commit the physical CPU.
• Committing CPU cycles.
• Use this functionality to resolve performance
  issues or set priority.

14
Performance Tips for ESX Configuring VMware for
SAP

• Setting the HAL
• When going from 1 vCPU to multiple vCPUs be sure
  the HAL is updated to reflect the change.
• When adding a vCPU the guest OS will normally
  detect the change and update the HAL. When
  removing a vCPU this does not happen.
• Guest placement
• Similar guest operating system should be
  configured on the same ESX host or cluster.
• Linux and Windows on the same host can cause
  contention.
• Provision supported guests.
• Balance provisioning between applications.

15
Performance Tips for ESX Configuring VMware for
SAP

• Screen savers and x-server.
• Screen savers, and X servers consume extra CPU.
• Impacts performance of other VMs.
• Impacts DRS.
• Disconnect devices.
• For example Windows polls CD devices regularly.
  When multiple guests poll simultaneously it
  impacts guest performance.

16
Performance Tips for ESX Configuring VMware for
SAP

• SAP w\ SQL
• Dynamic Allocation
• Admin can set a range of memory sizes SQL can
  allocate up to the max amount of memory and in
  theory release it when not used.
• Fixed \ Static Allocation
• Creates a fixed memory space for SQL to work
  with.
• Choose fixed \ Static memory allocation.
• This will avoid the allocation overhead of
  dynamic memory allocation.

17
Performance Tips for ESX Configuring VMware for
SAP

• Links
• http//www.vmware.com/company/news/releases/sap_fu
  llsupport.html
• http//www.vmware.com/files/pdf/partners/VMware_SA
  P_Software_Solutions_Deployment_Guide.pdf
• http//pubs.vmware.com/vi301/wwhelp/wwhimpl/js/htm
  l/wwhelp.htm
• http//www.vmware.com/partners/alliances/technolog
  y/sap.html