Storage vMotion Enhancements

Improved scalability

Improved performance

Less resource utilization

UI support

Migrate between thick and thin disks

Convert RDMs to VMDKs

No memory doubling requirement

Move a VM's storage from VMFS to NFS

Change storage while VM is running

Quick Hit - New vSphere 4 Storage Features

Paravirtualized iSCSI

What: This is a driver for high performance storage adapters

Benefits: It offers greater throughput and lower CPU utilization

When to use it: For very I/O intensive applications

VMDirect I/O for Storage

What: Enables VMs to directly access the underlying hardware

Benefits: Enhances CPU efficiency in applications with constant and frequent I/O

Drawbacks:
     1) VMotion is not available
     2) HBA is not shareable by other VMs

Virtual Disk Thin Provisioning

What: Space is allocated on an as-needed basis in 1 MB chunks

Benefits:
     1) Improves storage efficiency
     2) Increases utilization rates
     3) Reduces storage costs

Drawbacks: You could over provision the disks and run out of space, so monitoring of resources is essential.

How to Enable Hot Add CPU and Memory in vSphere

In vSphere, there is a new feature, hot add memory and CPU. This is very cool as downtime can be avoided which is, at least in my company, very helpful during daily operations. This feature is not enabled by default. To enable these features, do the following:

1. Make sure the virtual machine hardware is upgraded to version 7, if it is not, then right click the VM and choose 'Upgrade Virtual hardware'. You can find the hardware version by clicking on the 'Summary' tab.



2. Go to edit settings for the VM, then the options tab, under 'Advanced', select 'Memory/CPU hotplug' and in the pane to the right, enable the memory hot add and CPU hot plug features. This change must be made when the VM is powered down. If the VM is running, the options will be greyed out as in the image below.



Hot add memory and CPU is not supported by all OS's, Windows 2008 Enterprise 64 bit edition is one of the suppoted OS's, for a complete list, take a look at the Guest OS Guide.

Windows 2008 Activation - 0x8007232B – DNS name does not exist

When trying to activate a Windows 2008 standard server recently, I received error '0x8007232B - DNS name does not exist'.  The error description 'DNS name does not exist' can be misleading, the error occured because an invalid product key was entered.  If you didn't enter a product key during setup and then try to activate you will also receive this error.  Just correct the product key and activation will work.

Restart VMware Management Service

When all else fails..., run:

"service mgmt-vmware restart"

Recycling this service has cleared up many errors, I keep it handy. Case in point, the following error was thrown and then I lost control of the CD-ROM in one of my VMs. I recycled the VM and I still couldn't access the CD.

Error message:




Before recycling service:



After recycling service:

The Session is not Authenticated

When using the VMware vCenter Converter Standalone tool, you may find that when you get to step 2 - 'Specify Destination', you sometimes get the error 'The session is not authenticated'. There are two possible fixes that I know of. First, try killing the vmware-converter-a.exe process from task manager. If that does not work, you are probably converting a live machine, so go to that machine and recycle the 'VMware vCenter Converter Agent' service.

Mount and Unmount a CD in Linux

Mount:

mount -t auto /dev/cdrom /mnt/cdrom

Unmount:
umount /mnt/cdrom

In case of 'device is busy' when unmounting, try the 'lazy' unmount:
umount -l /mnt/cdrom