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vmnic/vmhba sequence changed in ESXi 5.5

Looks like VMware has made a small but momentous change to the vmnic/vmhba numbering with the release of vSphere ESXi 5.5. In previous versions, the vmnic numbering was always determined by the the PCI ID. After adding a new ESXi Host to a Cluster that has been updated from ESXi 5.1 to ESXi 5.5 i noticed that the vmnic numbering was inconsistent although all host were identical. The newly installed host has a different vmnic to PCI ID assignment compared to the hosts that have been updated from ESXi 5.1:


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ESXi 5.5 with PowerPath/VE 5.9 - Inaccessible Local Datastores

After upgrading an ESXi Host to version 5.5 and installing the current multipathing driver from EMC (PowerPath/VE 5.9) I encountered a problem with the local storage. EMC PowerPath claims the local storage and makes it inaccessible. The ESXi is unable to boot after it tried to claim the local devices. It boots one last time after installing the driver but can't access the local VMFS datastore. After a second reboot, an error message "No hypervisor found." is displayed in the VMware Hypervisor Recovery mode. From now on, the ESXi Host does not boot and needs to be reinstalled.


The main cause for that issue can be found after the first (and last) reboot next to the PowerPath/VE 5.9 installation in /var/log/vmkernel.log:

ALERT: PowerPath:Could not claim path vmhba1:C0:T0:L1. Status : Failure
WARNING: ScsiPath: 4693: Plugin 'PowerPath' had an error (Failure) while claiming path 'vmhba1:C0:T0:L1'. Skipping the path.
ScsiClaimrule: 1362: Plugin PowerPath specified by claimrule 290 was not able to claim path vmhba1:C0:T0:L1. Busy
ScsiClaimrule: 1594: Error claiming path vmhba1:C0:T0:L1. Failure.

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vCenter and the physical or virtual discussion - vSphere 5.5

Since vSphere 5.1 I have heard many advises that it is better to have a physical vCenter due to its enormous resource requirements. In the last years I had many discussions on that topics and it turned out that most people are just afraid because of this "chicken and egg" situation. Technical arguments are mostly related to dvSwitch issues or resource worries. In the following post I'll cover both sides of the argument.


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Upgrade vCenter 5.1 to 5.5 error: "The existing ssl certificate is invalid"

The upgrade from vCenter Server 5.1 to vCenter Server 5.5 (5.5.0 and 5.5.0a) fails during the SSO installation with the following error message:

The existing ssl certificate is invalid

After verifying the certificate i could confirm that it is valid and not expired. After troubleshooting the update log I figured out that the problem was caused by a wrong registry entry. The old 5.1 installation was using an IP address instead of the vCenters FQDN.

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Warning 25000 at vCenter 5.5 Update - How to handle?

When you are updating VMware vCenter Server 5.1 to version 5.5 you always get that "Warning 25000" message. This post shows how to check that the certificate is valid, and how to replace a expired certificate

Warning 25000. Please verify that the SSL certificate for your vCenter Single Sign-On 5.1 SSL is not expired. If it did expire, please replace it with a valid certificate before upgrading to vCenter Single Sign-On 5.5.

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Howto: AD Authentication in vCenter SSO 5.5

With the recently released VMware vSphere 5.5, the component Single-Sign-On (SSO) has been completely rewritten. The biggest change is that the RSA database has been removed, which eliminates much of its complexity. There is also a new identity type (Active Directory (Integrated Windows Authentication)) that works without specifying the AD Controllers directly, like the old vSphere 4.x / 5.0 authentication. The whole process is much easier. This post shows how to enable Active Directory Authentication within the new vSphere 5.5 Single-Sign-On. If you are using vSphere 5.1, read this post.

The method shown in this post allows you to manage users and groups in your central directory. This works for both, the vCenter Server 5.5 installed on Windows Server and the vCenter Server Appliance (VCSA).

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VMware vCenter Server Appliance 5.5 (vCSA) Limitations

vCenter Server Virtual Appliance (vCSA) is still very rare in a production environment. This might change with the current enhancements to the scalability made in vSphere 5.5. The maximum supported numbers of the embedded database have been lifted to 100 ESXi hosts and 3000 virtual machines. From now on, there are only a few imitations remaining. I do not think that many environments hit the scale limit, so the only remaining limitations are Windows-related limitations.

Here are the limitations from VMware vCenter Server Appliance 5.5

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