VSP3867 Top 10 Virtualization Support Issues

1. VSP3867Top 10 Virtualization Support Issues Name, Title, Company

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4. Journey to IT Transformation – Accelerate and Amplify Enterprise Hybrid Cloud Cloud High Governance Low Governance Infrastructure focus Application focus Business focus Virtualization IT Production Business Production IT as a Service

5. Top 10 Support Issues “An ounce of prevention is worth a pound of cure!” • Identify the most common topics our customers engage us with. • Anticipate the potential problems you may encounter. • Prepare an action plan to address these problems. • Become informed on the most frequent support topics before you encounter them.

6. Top 10 Support Issues • VMotion CPU Compatibility • Problem: • CPUs need to preferably be identical for certain operations such as FT and VMotion. If they are not, compatibility warnings are shown or the operations may not be possible • Symptoms: • CPU Compatibility messages • Virtual machine failures or crashes • Recommendations: • Do NOT use CPU masking. USE Enhanced VMotion Compatibility (EVC) • Buy servers in bunches (3 to 4 or more) that all are identical. • Keep AMD and Intel servers in different clusters

7. Top 10 Support Issues (2) • vCenter Database size • Problem: • The size of the vCenter database grows very large. • Symptoms: • Database files / Transaction logs grow large • Deadlocks occur when processing performance data • Recommendations: • Most database size problems occur due to statistic or Task/Event information • Check that the agent service is running or performance data will not be processed • Check that adequate RAM and CPUs exist on the SQL Server • Perform regular database maintenance such as backups and defragmentation of the indexes

8. Top 10 Support Issues (3) • vCenter shows high Memory utilization in vCenter 4 • Problem: • Newer processors that have built in virtualization support and can utilize large pages show what appears to be large memory usage of the VMs and ESX. • Resolution: • None, there is no problem here! • Large Pages provide a performance increase of ~25% on heavy workloads such as SQL Databases • Memory usage shown is actually consumed memory and should not be used as the only indicator of memory utilization. • If memory usage is never above 80% than vSphere features such as over commitment ballooning and transparent page sharing will never be used • Look at swap-in/swap-out, and active memory to get a better view of the memory utilization taking virtualization overhead into account. • Disabling large pages will move the behavior back to pre vCenter 4 views, but the benefits of having them enabled out weigh the drawbacks. VMware does not recommend disabling Large Pages.

9. Top 10 Support Issues (4) • VMware HA Configuration fails • Problem: • Commonly HA will sometimes fail with “ HA Agent has an error” • Recommendations: • Make sure that the ESX Servers are able to ping each other and the configured default gateway or configuration will fail • Most common problems configuring HA are in the following categories: • DNS Name Resolution • Networking Configuration • Time Configuration • For further troubleshooting regarding VMware HA, see Troubleshooting VMware High Availability (HA) (1001596)

10. Top 10 Support Issues (5) • vCenter / ESX Upgrade issues • Problem: • Upgrades of vCenter sometimes are not as easy as pointing and clicking. A lot of cases are not problems but an issue where best practices are not followed. • Recommendations: • Most of the problems seen can be avoided by • Ensuring that there are enough resources available, most importantly disk space • Ensure that the database revision is still supported (SQL 2000 is not in vSphere 4) • BACKUP BACKUPBACKUP the vCenter database • Permissions on the vCenter Database and the MSDB • Make sure the host is 64-bit, as it is a requirement for ESX4. • Detach the SAN for ESX Upgrades to local disks, otherwise make sure to install to the proper LUN • Always follow the practices in Upgrading to ESX 4.0 and vCenter 4.0 best practices (1009039)

11. Top 10 Support Issues (6) • ESX Servers show not responding in vCenter • Problem: • ESX Hosts may show not responding in vCenter and customers will reboot the host rather than troubleshooting. • In the most general of terms this will happen for two reasons: • Network problems (including ESX Firewall) • ESX Management service problems • Recommendations: • If Console login is possible, then many times a whole host reboot can be avoided. • Review the ESX Host Logs vpxa.log, hostd.log and vmkernel.log for clues as to what is happening • Look out for: • storage errors (most common reason for hostd service issues) • Service console available memory / CPU • Third party interaction (SDK, etc.)

12. Top 10 Support Issues (7) • Snapshots! • Many misconceptions of snapshots function • Snapshots are meant for point in time restores, while doing maintenance in the VM • Not meant to be kept for long periods of time • Data is not stored in the VMDK, rather in a sparse outside the allocated disk space • There are a multitude of snapshot related issues: • Using them as backups • Nested snapshot trees • Corruption of snapshot tree due to inadvertently powering on the base disk • Recommendations • Whenever adding an existing disk to a new virtual machine make sure you are not adding a parent disk. (GUI does not display snapshots!) • Use a proper product such as VCB to do your backups. This will prevent large nested snapshot trees and use the technology properly. • If you are using them make sure adequate space is available on the LUN

13. Top 10 Support Issues (8) • All Paths Down (APD) state disrupts virtual machines on unrelated LUNs • Issue: • During an APD condition the ESX Storage layer retries I/Os to VMFS datastores. • Rescan operations take a long time. • Symptoms: • Virtual machines on unaffected LUNs appear to be unresponsive. • Workaround/Resolutions • Mask the LUNs in question. Follow the instructions in Unpresenting a LUN containing a datastore from ESX 4.x and ESXi 4.x (1015084) • VMware has fixed the problem in ESX4.0 P3 ( ESX400-200912001 on the download site)

14. Top 10 Support Issues (9) • Cannot connect to View Desktop • Problem: • Client cannot properly connect to the View connection server • Symptom: • Generic error messages saying “Cannot Connect to Desktop” • Resolutions: • External configuration issues are the normal cause for this when connecting to a desktop fails • Network configuration • Firewalls • Incorrect version of the View client, agent, and/or connection server. Verify the version is appropriately matched. • Collect the View log files and validate if there is any more specific error message to indicate a problem in the logs. For more information , see Collecting diagnostic information for VMware View 3.x and 4.0.x (1017939)

15. Top 10 Support Issues (10) • PCoIP Multi-Monitor configurations with Windows 7 in View v4.0.x • Problem: • Both screens may not be detected or may flicker a lot before it stabilizes • Resolution: • Officially this is an unsupported experimental configuration with View 4.0.x . • Full support has been added in View v4.5.x and newer versions. Updating will allow this functionality. • Workarounds: • To get it to work, add more Video RAM to the virtual machine (bigger multiples of 64 are better) will sometimes resolve the problem • Confirm that the VMX file properly is configured to use two monitors • Editing the default resolution and monitor configuration in the settings of the desktop pool within View.

16. Top 10 Support Issues Summary • Each of these problem areas could be encountered in your own infrastructure. • Identifying the most common problems allows you to anticipate them and develop a plan to prevent these issues before they occur. • Stay up to date with software patches and updates. Be sure to read the release notes and understand what issues are addressed in each release.