Enable/Disable certificate checking on Esxi Host

The data that travels between clients and ESXi hosts is encrypted to ensure that the transactions are private and authenticated. The SSL is used to create a secure connection between the clients, ESXi hosts, and/or the vCenter Server.  SSL uses TCP/IP and allows SSL-enabled ESXi hosts and/or vCenter Server to authenticate with SSL-enabled clients. 

When an ESXi host or vCenter Server is installed, the installation includes SSL certificates. These preinstalled, auto generated certificates are not from an official certificate authority (CA), but they can be used to establish an initial connection.

The vCenter Server uses an SSL certificate when adding ESXi hosts and to connect to managed ESXi hosts whose passwords are stored in the vCenter Server database. After an authenticated encrypted connection is established, a smaller session key is encrypted and exchanged using public and private key pairs.

This shared session key is then used to encrypt and decrypt the data between client and server.Read More

Refresh/Regenerate/Replace Esxi 6.0 SSL Certificates

To improve security in your virtualized environment, it is advisable to use the signed certificates because  ‘self-signed’ certificate will not be trusted by default in it’s communications with other systems. There are various ways to deploy signed certificates on your Esxi hosts and in this post we will look at available options.

Refreshing Esxi Certificates

If you have updated the certificate information and want to push those changes to certificate installed on Esxi host, the simplest method is to do a refresh certificate. Lets understand this by an example.

Suppose this is the current configuration of the vCenter certificate where country name is US and Org Unit is “VMware Engineering”

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Now suppose you have updated the various configuration value for your vCenter certificate as shown below

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Now if you select the Esxi host and navigate to Manage > Settings > Certificates, you will see it still contains the old information i.eRead More

Configure and manage VMware Endpoint Certificate Store

VMware Endpoint Certificate Store (VECS) serves as a local repository for certificates, private keys, and other certificate information that can be stored in a keystore. You can decide not to use VMCA as your certificate authority and certificate signer, but you must use VECS to store all vCenter certificates, keys, and so on. ESXi certificates are stored locally on each host and not in VECS.

VECS runs as part of the VMware Authentication Framework Daemon (VMAFD). VECS runs on every embedded deployment, Platform Services Controller node, and management node (vCenter) and holds the keystores that contain the certificates and keys.

VECS polls VMware Directory Service (vmdir) periodically for updates to the TRUSTED_ROOTS store. You can also explicitly manage certificates and keys in VECS using vecs-cli commands.

VECS Default Stores

1: Machine SSL Store (MACHINE_SSL_CERT)

This store is used by the reverse proxy service on every vSphere node. This store is also used by the VMware Directory Service (vmdir) on embedded deployments and on each Platform Services Controller node.Read More

Replacing vSphere 6.0 certificates using VMCA as a Subordinate CA

vSphere 6.0 brought many enhancements with it and one of the most significant among them was VMware Certificate Authority which is VMware’s own CA and it eases the pain of certificate management in vSphere 6.

VMCA is itself a fully functional CA and can be used to issue certificates to all vSphere 6 components (vCenter and ESXi hosts) in your environment. VMCA dont have any graphical interface like Microsoft CA and is totally command line driven.

VMCA is part of Platform services controller and there are various deployment model available for configuring VMCA including:

  • VMCA as Root CA
  • VMCA as Subordinate CA to an External Enterprise CA
  • External CA
  • Hybrid mode

Derek Seamen has explained about these deployment options in greater detail here

By default, the VMCA self-signs its own certificate which is used by vCenter server and Esxi hosts. If  your organization policy don’t allow using self-signed certs then you can replace the certs generated by VMCA and sending them to an enterprise CA for signing.Read More

Backup and Restore Resource Pool Configurations

When DRS is disabled on a cluster, it removes all the resource pools that are part of the cluster and the resource pool hierarchy and affinity rules are not re-established when DRS is turned back on. 

Now if you really want to disable DRS (for any maintenance activity) and want to save yourself from the pain of re-creating resource pools and configuring share/limits etc, you can take backup of resource pools and and restore it later post completing the maintenance and enabling DRS again.

In my lab I created a resource pool named “RP-Edge” and placed one VM in this resource pool.

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When you disable DRS on a cluster, vSphere gives you an opportunity to save the resource pool tree in a file which can be used later to restore the resource pool hierarchy.

Just click on yes on the warning window presented.

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save the file on your local PC.

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At this point, the resource pool is gone and the Win-DR-Test VM is out of the resource pool.… Read More

Backup and Restore vDS Configurations

You can export vSphere distributed switch and distributed port group configurations to a file. The file preserves valid network configurations, enabling distribution of these configurations to other deployments.

This functionality is available only with the vSphere Web Client 5.1 or later. However, you can export settings from any version of a distributed switch if you use the vSphere Web Client or later.

To export vSphere Distributed Switch configurations using the vSphere Web Client:
 
1: Browse to a distributed switch in the vSphere Web Client navigator and Right-click the distributed switch and click Settings > Export Configuration
 

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2: Select the Export the distributed switch configuration or Export the distributed switch configuration and all port groups option.

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3: Click Yes to save the configuration file to your local system. 

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Select a location your computer where you want to save the backup file and also provide a name for the backup file.

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You now have a configuration file that contains all settings for the selected distributed switch and distributed port group.Read More

Troubleshooting vSphere Replication plugin missing from vCenter Server

Last week I upgraded my VR appliance from 6.1.1 to 6.1.2 and registered VR to vCenter and to my surprise VR plugin was missing after I reloaded my vSphere Web Client. I tried logoff and login to Web Client a couple of times, but luck was not with my side. 

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While configuring VR, I saw a succesful configuration message, So easily I can rule out issues with VR > VC registration. 

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I even restarted Web Client service followed by bouncing vCenter server node but VR has decided to give up on me that day and still the plugin was missing from Web Client. This was a bit strange for me as I have deployed VR in my lab 3-4 times and never encountered this issue.

On googling the issue, I came across VMware KB-2149560 which clearly mentions that this is a known issue with VR 6.1.2. The KB has all the steps listed in order to fix the issue. … Read More

vSphere Replication & Multi Point in Time Snapshots

When configuring replication of a virtual machine, you might have noticed the option “Point in time instances” aka PIT. This setting allow for some snapshots to be maintained at the DR site for the replicated VM at certain intervals.  

During replication, vSphere Replication replicates all aspects of the virtual machine to the target site, including any potential viruses and corrupted applications. The benefit being that if a guest is corrupted, we have multiple points in time to failover from in case the corruption already replicated across sites

vSphere Replication retains a number of snapshot instances of the virtual machine on the target site based on the retention policy that you specify. vSphere Replication supports maximum of 24 snapshot instances. After you recover a virtual machine, you can revert it to a specific snapshot.

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Multiple Point In Time (MPIT) recovery was first introduced in vSphere replication 5.5 and it enables an administrator to recover a virtual machine to the latest replicated copy at the target site and then revert, or “roll back,” that virtual machine to a previous point in time.Read More

Replicating VM between sites using vSphere Replication

Once your primary and DR site is ready, you can start replicating VM’s between the sites and test the failover/failback etc to ensure your disaster recovery plans are functioning well and you will be protected when actual disaster happens in your on-premise datacenter.

In this post we will learn how to replicate VM from one vCenter to another which is in DR site. Lets get started.

Navigate to VM and template view in vCenter server in your source site and select the VM which you want to replicate to the DR site. Right click on the VM and chose All vSphere Replication Actions > Configure replication

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vSphere Replication can be used to replicate VM’s to the local DR site as well as to a cloud provider side such as vCloud Air . In our example we are going for a local DR site replication so I chose Replicate to a vCenter Server. Read More

vSphere Replication 6.0 Compression Method

With vSphere Replication 6.0, VMware added a new feature named “Network Compression” and you have noticed this while configuring replication for a virtual machine. 

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What is Network Compression?

It is a method for compressing the replication data that is transferred through the network which helps in saving network bandwidth and might help reduce the amount of buffer memory used on the vSphere Replication server. However, compressing and decompressing data requires more CPU resources on both the source site and the server that manages the target datastore.

Do you really need network compression in your infrastructure?

vSphere Replication uses CBT technique to replicate changed blocks to a DR site (which commonly exists in cloud these days) and the DR site is usually connected to primary site via a WAN link. These WAN links typically have limited bandwidth or high latency. Network compression can save your precious WAN bandwidth.

VR data compression support

vSphere Replication 6.0 supports end-to-end compression when the source and target ESXi hosts are also version 6.0.Read More