VMware vSphere hot add is a feature that allows vSphere administrators to increase the RAM and CPU capacity of a running virtual machine on the fly. This feature is one of my favourites (second to vMotion). Hot add of CPU is usually referred as hot-plug, but I will be using term hot add for both RAM & CPU.

What so special about hot-add?

Think of older times when a physical server used to run out of resources (cpu/memory) and the administrator has to do shutdown the server to increase the capacity of server. Shutting down of server itself was a big headache in those time as the administrator has to get approval from the application owner, create a change request for maintenance etc etc.

At that time if someone would have explained me that you can add CPU/RAM into a server in running condition, I would have laughed hard on him and may be I would have given him titles like mad,crazy and what not.… Read More

When a virtual machine is created, there are number of files that are created alongwith. The most important among them is the .vmx file which is the configuration file of the VM. Whatever settings we chose during deployment of virtual machine, is written in this file along with many other configuration settings.

Although most of the virtual machine settings can be edited via web client, we can modify the vmx file directly (not recommended though) also to change configuration settings or to add some extra configuration items.

When we edit the virtual machine settings from Web Client, those settings are written in vmx file of the vm. To do so the VM needs to be in powered-off state.

To modify the settings of a virtual machine, login to Web Client and select VM from the inventory and navigate to Manage > Settings > VM Options > Advanced settings and click on Edit button to make changes to the current configuration.… Read More

In this post we will discuss about the different type of scsi controllers that are available with VMware vSphere and when to use which type of controller. We will discuss following topics in this post:

• What is SCSI controller and their types
• Why SCSI controller selection is so important
• Storage Controller Compatibility
• Adding/Changing SCSI controllers in virtual machines
• Changing controller type by modifying virtual machine vmx file

so lets get started.

What is SCSI controller and their types?

SCSI controllers are used by virtual machine to access SCSI disks and other SCSI devices such as CD/DVD ROM. SCSI controllers are added automatically when a VM is deployed. Controllers can be added/modified also post creation of VM.

When a VM is created, the default controller that is assigned to it is optimized for best performance and the controller selection depends purely on the guest OS chosen at the time of VM creation.… Read More

VUM Orchestrated upgrades allow you to upgrade the objects in your vSphere inventory in a two-step process: host upgrades followed by virtual machine upgrades. If you want the upgrade process to be fully automated, you can configure it on cluster level or you can configure this at the individual host or virtual machine level for granular control.

Before going ahead with orchestrated upgrade, we have to ensure that we have baseline groups created for hosts as well as VM’s. I will talk more on this later in the post.

In orchestrated upgrade, we have to first remediate the cluster against the host upgrade baseline (we covered creation/remediation in our last post). Once the hosts are upgraded, we remediate the same cluster against a virtual machine upgrade baseline group containing the VM Hardware Upgrade to Match Host and VMware Tools Upgrade to Match Host baselines.

How Orchestrated upgrade works?

• Orchestrated upgrade of ESXi Hosts

Patches/extensions and upgrades can be applied to an Esxi host by using host baseline group.… Read More

In last post we learn how to configure UMDS and how to enable VUM to use shared repository for downloading patches. If you are new to VUM/UMDS and by mistake landed directly on this page, I would encourage reading about them first from below links:

1: Installing vSphere Update Manager and Update Manager Download Service

2: Configure Update Manager Download Service

Also in past I have written one blog post on Creating Esxi hosts baselines and how to remediate host. You can read that post from here.

In this post I will be covering below objectives:

• Configure hosts/cluster settings
• Create VUM baseline group
• Manually download updates to a patch repository
• Import Host upgrade images and upgrade Esxi hosts.
• Configure Smart Rebooting for vApps

Lets get started.

1: Configure hosts/cluster settings

To configure hosts  maintenance mode settings, Login to Web Client and Click on  Update Manager icon from home page and naviate to Manage > Settings > Host and clusters settings >> Edit.… Read More

Last year I wrote a post on how to install and configure VUM and UMDS, but never got chance to connect UMDS to VUM and ended up downloading patches directly on VUM server via internet.

Once again I am playing with UMDS in lab and in this post we will cover why we need UMDS and how to configure it.

I am not covering steps for installing VUM/UMDS here because they are pretty straight forward and if you are new to these things, you can read the instructions about installation steps from here.

What is Update Manager Download Service?

Update Manager Download Service (UMDS) is an optional component which you can deploy with update manager. We can download upgrades for virtual appliances, patch metadata, patch binaries and notifications etc using UMDS.

Why we need UMDS when VUM is there?

Its a obvious question to ask that why we need UMDS when VUM is capable of downloading and installing patches on Esxi hosts/vApps.… Read More

Yesterday while reading about Enhanced linked mode I stumbled across this blogpost by William Lam where he have demonstrated how to split vCenters which are configured in linked mode.

I thought to give it a try in my lab also as these days I am playing around PSC’s and repointing, ELM things etc.

In my lab I have 2 PSC nodes and 2 vCenter server nodes each pointing to one of the PSC. Both PSC nodes are in same SSO domain/site

Both PSC are replicating to each other. Also I have verified that I do not have any stale entries for any PSC nodes from my existing lab activities.… Read More

Linked Mode was first introduced in vSphere 4.x and it has come a long way with vSphere 6.0.

Enhanced linked mode (ELM) allows administrators to manage multiple vCenter servers from one place using vSphere Web client. vCenter servers in ELM can replicate roles, permissions, licenses and policies between them.

ELM also enables Cross vCenter vMotion i.e you can migrate virtual machines across clusters on separate vCenter instances; subject to network limitations.

Previously linked mode configuration was only possible with Windows based VC as ADAM was used as the replication engine between the VC’s.

ELM in vSphere 6.0 don’t rely on ADAM anymore but have its own replication system which is a multi-master replication technology also called VMDir based on Open LDAP which means replication now works across Windows vCenter as well as vCenter appliances.

Note: All vCenters configured in ELM can be managed only from Web Client. If you are using vSphere C# client then you can only manage that vCenter server to which you are connected.… Read More