Yellow Bricks

by Duncan Epping

4.1

32-bit ODBC DSN for VUM 4.1

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My VMware Cloud Team colleague Max Daneri of VMTS fame was building a vSphere 4.1 environment this week. During the installation of VUM(VMware Update Manager) he ran into an issue with the database connection which I thought would be useful to share with you. After some playing around he found out that apparently VUM requires a 32-bit ODBC DSN. Which was a surprise as VUM requires a 64-bit OS.

Of course we should have read the documentation first as it is stated on page 27 of the VUM Install Guide…

IMPORTANT: Although you can install the Update Manager server only on 64-bit machines, Update Manager is a 32-bit application and requires a 32-bit DSN.

vSphere 4.1, VMware HA New maximums and DRS integration will make our life easier

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I guess there are a couple of keypoints I will need to stress for those creating designs:

New HA maximums

  • 32 host clusters
  • 320 virtual machines per host
  • 3,000 virtual machines per cluster

In other words:

  • you can have 10 hosts with 300 VMs each
  • or 20 hosts with 150 VMs each
  • or 32 with 93 VMs….

as long as you don’t go beyond 320 per host or 3000 per cluster you are fine!

DRS Integration

HA integrates on multiple levels with DRS as of vSphere 4.1. It is a huge improvement and it is something in my opinion that everyone should know about.

Resource Fragmentation

As of vSphere 4.1 HA is closely integrated with DRS. When a failover occurs HA will first check if there are resources available on that host for the failover. If resources are not available HA will ask DRS to accommodate for these where possible. Think about a VM with a huge reservations and fragmented resources throughout your cluster as described in my HA Deepdive. HA, as of 4.1, will be able to request a defragmentation of resources to accommodate for this VMs resource requirements. How cool is that?! One thing to note though is that HA will request it, but a guarantee can not be given so you should still be cautious when it comes to resource fragmentation.

DPM

In the past there barely was integration between DRS/DPM and HA. Especially when DPM was enabled this could lead to some weir behaviour  when resources where scarce and an HA failover would need to happen. With vSphere 4.1 this has changed. In such cases, VMware HA will use DRS to try to adjust the cluster (for example, by bringing hosts out of standby mode or migrating virtual machines to defragment the cluster resources) so that HA can perform the failovers.

Shares

I didn’t even found out about this one until I read the Availability Guide again. Prior to vSphere 4.1, an HA failed over virtual machine could be granted more resource shares then it should causing resource starvation until DRS balanced the load. As of vSphere 4.1 HA calculates normalized shares for a virtual machine when it is powered on after an isolation event!

vSphere 4.1: Datacenter.QueryConnectionInfo failed?

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When I was installing vSphere 4.1 ESXi I ran into a problem. I received the following error when I added the ESXi host to my cluster:

Call “Datacenter.QueryConnectionInfo” for object “yellow bricks” on vCenter Server “W2K8-001” failed.

Although the error didn’t make much sense I had the feeling it had something to do with name resolution(This KB article gave a hint I guess). After I added my dns suffix on my NIC it worked. Problem solved.