Virtualization, High Performance Computing, Enterprise Computing

November 2009

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vSphere Update One – Avoid the Purple Screen of Death And Other Issues During Upgrade.

November 30, 2009 in VMware by Rod | No comments

If you have not yet updated to vSphere Update One, this post is for you to avoid the purple diagnostic screen of death with the error “COS Panic: Int3 @ mp_register_ioapic ” when upgrading from ESX 4.0 to 4.0 U1 after a reboot. ( Specifically if you are using HP’s insight management agents in the COS. )

See KB Article 1016070 for the latest.

Basically SHUT DOWN all HP COS agents before upgrading. This is only for ESX and not ESXi since there is no COS in ESXi. You should also examine 3rd party agents and plugins for compatibility in the lab before upgrading in production. For example, EMC storage viewer is broken with vSphere Update One, slated to be fixed in the EMC 2.1 release.

Make sure to read all the release notes and manual before attempting the upgrade, and have backups of course:

The vSphere Update One release notes:
http://www.vmware.com/support/vsphere4/doc/vsp_vc40_u1_rel_notes.html

The vSphere Upgrade Checklist here:
http://www.vmware.com/files/pdf/vsphere-migration-prerequisites-checklist.pdf

The vSphere Upgrade guide here:
http://www.vmware.com/pdf/vsphere4/r40/vsp_40_upgrade_guide.pdf

As any new items pop up, we will update this post.

Tags: vSphere Update One

vSphere Update 1 is Available

November 20, 2009 in Uncategorized by Rod | No comments

The following information provides highlights of some of the enhancements available in this release of VMware ESX:

VMware View 4.0 support – This release adds support for VMware View 4.0, a solution built specifically for delivering desktops as a managed service from the protocol to the platform.

Windows 7 and Windows 2008 R2 support –This release adds support for 32-bit and 64-bit versions of Windows 7 as well as 64-bit Windows 2008 R2 as guest OS platforms. In addition, the vSphere Client is now supported and can be installed on a Windows 7 platform. For a complete list of supported guest operating systems with this release, see the VMware Compatibility Guide.

Enhanced Clustering Support for Microsoft Windows – Microsoft Cluster Server (MSCS) for Windows 2000 and 2003 and Windows Server 2008 Failover Clustering is now supported on an VMware High Availability (HA) and Dynamic Resource Scheduler (DRS) cluster in a limited configuration. HA and DRS functionality can be effectively disabled for individual MSCS virtual machines as opposed to disabling HA and DRS on the entire ESX/ESXi host. Refer to the Setup for Failover Clustering and Microsoft Cluster Service guide for additional configuration guidelines.

Enhanced VMware Paravirtualized SCSI Support – Support for boot disk devices attached to a Paravirtualized SCSI ( PVSCSI) adapter has been added for Windows 2003 and 2008 guest operating systems. Floppy disk images are also available containing the driver for use during the Windows installation by selecting F6 to install additional drivers during setup. Floppy images can be found in the /vmimages/floppies/ folder.

Improved vNetwork Distributed Switch Performance – Several performance and usability issues have been resolved resulting in the following:

•Improved performance when making configuration changes to a vNetwork Distributed Switch (vDS) instance when the ESX/ESXi host is under a heavy load
•Improved performance when adding or removing an ESX/ESXi host to or from a vDS instance

Increase in vCPU per Core Limit – The limit on vCPUs per core has been increased from 20 to 25. This change raises the supported limit only. It does not include any additional performance optimizations. Raising the limit allows users more flexibility to configure systems based on specific workloads and to get the most advantage from increasingly faster processors. The achievable number of vCPUs per core depends on the workload and specifics of the hardware. For more information see the Performance Best Practices for VMware vSphere 4.0 guide.

Enablement of Intel Xeon Processor 3400 Series – Support for the Xeon processor 3400 series has been added. For a complete list of supported third party hardware and devices, see the VMware Compatibility Guide.

Tags: vSphere

Thick vs Thin Disks with VMware

November 15, 2009 in Uncategorized by Rod | No comments

VMware has a great new performance whitepaper on thin vs thick disk performance:

http://www.vmware.com/pdf/vsp_4_thinprov_perf.pdf

The summary is there is no performance impact when using thin provisioned disks compared to thick disks with VMware.

NetApp has a great resource for Thin vs Thick Basics:

http://blogs.netapp.com/virtualstorageguy/2009/10/vce-101-thin-provisioning-part-1-the-basics.html )

and a followup article looking at the advantages of de-dup and thin provisioning at the array level:

http://blogs.netapp.com/virtualstorageguy/2009/10/vce-101-thin-provisioning-part-2-going-beyond.html )

NetApp and VMware Guest Timeout

November 10, 2009 in NetApp by Rod | No comments

During a recent customer VMware healthcheck, we noted a customer did perform the VMware NFS timeout tunings as recommended by NetApp TR-3749. However none of the guests had the correct guest level timeout tuning.

TR-3749 doesn’t explicitely spell out that you should make sure and update your guest level disk timeouts to match the NFS timeout tunings.

Also note that these disk timeout settings if done once in the guest, may be reset through a VMware Tools upgrade. (See http://communities.vmware.com/thread/212235) so watch out.

See NetApp article kb41511 “VMware ESX Guest OS I/O Timeout Settings for NetApp Storage Systems” for more details.

Tags: NetApp, VMware

VMware Swap- Rules of Thumb with NetApp?

November 10, 2009 in NetApp by Rod | No comments

We frequently get questions from customers with NetApp if they should store the swap with the VM or on a separate datastore, and how big should they make their swap datastore.

NetApp recommends in NetApp TR-3749 to use a separate datastore, as to avoid storing “transient” data like swap when using array based snapshots or disk-to-disk replication with SnapMirror and/or SnapVault. (Also See TR-3428).

For sizing, you can thin provision and use autogrow on the NetApp side to avoid having to worry about an “exact” space figure as this space is dynamic in nature depending on the number of VM’s, the memory in those VM’s, and memory reservations, and is used only when there is memory pressure.

If you want an absolute worse case add up all the VM’s you would create with the memory you anticipate allocating to them, and use that result if you need an absolute worse case number.