Uncovering VMware vSphere 5.1′s “Best Kept Secrets” Part 1


by Bill Oyler | 06.04.2013
Categories: Blog

Since I first began implementing VMware’s enterprise-class hypervisor back in 2005 (which was then known as ESX 2), VMware has continued to innovate their flagship product with dozens of new features every year.  Most of these features are well publicized through the annual VMworld conference, VMware technical white papers, and various VMware-focused blogs.  However, as vSphere 5.1 approaches its 1-year anniversary, I am often surprised how many of its most useful features are being under-utilized in the field. 

In some cases, the end user is not aware of how these features work from a technical standpoint.  In other cases, the end user simply does not know about the existence of some of these features.  In still other cases, the end user does not realize that their licensing includes some of these features.  Whatever the reasons may be, I would like to spend some time going over these “best kept secrets” and how they can help make your VMware vSphere infrastructure more reliable and efficient – and ultimately make your job much easier!

#1:  vSphere Web Client

VMware has always had some form of a “web client,” but starting with vSphere 5.1, the new vSphere Web Client is becoming a “first class citizen” and the legacy Windows .NET-based vSphere Client is slowly being deprecated into a “second class citizen.”  VMware has stated that all new features, starting with version 5.1, will only be exposed in the Web Client.  Furthermore, the next “major” release of vSphere will only include the Web Client.  For these reasons, it is very important to install the Web Client and become familiar with the new user interface.  I have seen a number of cases where the Web Client is not even installed.  You can install it onto the vCenter Server using the “autorun” screen of the vCenter install media. 

A number of useful features that I am discussing below are only available in the Web Client, so please try to spend a little time exploring this new interface.  It is quite different from the Windows Client and will take some getting used to.  Certain activities are faster than the Windows Client, and certain activities are slower.  I personally find that the Chrome browser provides the fastest overall experience (compared with IE or Firefox).  I expect VMware will work on making this Web Client even faster with future updates.

One important consideration to be aware of is that there are a few features that are not available in the Web Client at the time of this blog publication.  Two big omissions are Update Manager and Site Recovery Manager.  As of vCenter 5.1 Update 1, the Web Client now supports a very small subset of Update Manager’s functionality, so you will still need to use the legacy Windows Client for Update Manager, as well as Site Recovery Manager.

For a (mostly) complete description of the features only available in the Web Client, and the features only available in the legacy Windows Client, see this blog post: 
  • TIP: After installing the Web Client, you must access it via the full URL and port number for it to properly initialize. 
  • TIP: Configure Single Sign On with your Active Directory domain as a “default domain” so that you can log in to the Web Client without specifying your domain name each time. 
  • TIP: If you install the optional Client Integration Plug-In, you will be able to:
    • Log in as current user.
    • View virtual machine console.
    • Upload/download files to/from datastores.

#2:  vSphere Replication

Have you ever wanted to create a copy of a virtual machine and have it periodically kept in sync, either at a remote datacenter or just as a secondary copy at the same datacenter?  In the past, you were required to purchase a third party software solution to automate this task.  However, starting with vSphere 5.1, virtual machine replication is built-in to the hypervisor and exposed via the new Web Client.  vSphere Replication is extremely easy to set up and manage.  Some of the capabilities of vSphere Replication include: 
  • Replicate up to 500 VMs.
  • Configurable RPO per VM between 15 minutes and 24 hours.
  • Replicate to the same datacenter/vCenter or to a different datacenter/vCenter.
  • Replicate on a per-virtual machine, per-virtual disk basis (replicate some or all virtual disks).
  • Replicate from any datastore to any datastore (any size, any type, including local disks).
  • Replicate from thick to thin and vice-versa.
  • Easily seed the virtual disks using a portable USB/NAS device.  Replica is hashed against source and only block-level changes are sent across the WAN.
  • You can use vSphere Replication in conjunction with storage array-based replication if desired.
  • vSphere Replication is Storage vMotion and Storage DRS-friendly in vSphere 5.1.
  • vSphere Replication supports Guest OS-level file system and application quiescing using the Microsoft VSS driver if desired.  (NOTE: Use caution with this setting, as it is brand new and relies on VSS operating correctly.)  
  • TIP: You can replicate virtual disks that are in VMDK format or Virtual Mode RDM format, but not Physical Mode RDM format.  For Physical Mode RDMs, you will need to use another form of replication, such as array-based replication.  (Better yet, try to eliminate Physical Mode RDMs!) 
  • TIP: vSphere Replication cannot replicate VMs that are Powered Off
  • TIP: Virtual machine snapshots will be “collapsed” on the replica copy.  Therefore only the “most current” version of the VM is replicated. 
  • TIP: vSphere Replication only transmits changed blocks, so it is very WAN efficient.  However, it does not perform deduplication or compression.  Use a third party WAN accelerator if desired.
  • TIP: vSphere Replication is included with the following vSphere licenses:
    • Essentials Plus
    • Standard
    • Enterprise
    • Enterprise Plus

#3:  “Enhanced” vMotion

vMotion has been around for about a decade, and Storage vMotion has been around for many years, but these features have always required shared storage (SAN or NAS).  Starting with vSphere 5.1 however, vMotion was “enhanced” to work without the requirement of shared storage (SAN or NAS).  In other words, you can migrate a virtual machine from local disk on Server A to local disk on Server B without downtime!  This capability has been referred to as “Enhanced vMotion” or “Unified vMotion” or “Shared Nothing vMotion” in various blogs and VMworld sessions.  In a nutshell, it is a combination of traditional vMotion (moving a VM from Host A to Host B) and Storage vMotion (moving a VM from Datastore A to Datastore B). 

In order to use this “Enhanced” vMotion, you must be running vSphere 5.1 and you must be using the Web Client.

Be sure to keep in mind the following requirements for “Enhanced” vMotion to work correctly:
  • Hosts must be managed by the same vCenter.
  • Hosts must be part of the same Datacenter.
  • Hosts must be on the same Layer 2 network (and same vSwitch if using Virtual Distributed Switch).
  • The vMotion vmkernel (LAN) interface is used for “shared nothing” migrations, but if the destination datastore exists on a shared storage fabric (such as Fibre Channel), the vMotion process will use the storage fabric for data migration, as is the case with a traditional Storage vMotion.
  • There is a maximum of 2 concurrent Storage vMotions (including Enhanced vMotion) per host.
  • DRS and SDRS do not use Enhanced vMotion technology at all, and will not make any recommendations for Enhanced vMotion migrations.
  • TIP: Remember that shared storage is still required for VMware HA!
  • TIP: “Enhanced” vMotion is included with the following vSphere licenses:
    • Essentials Plus*
    • Standard
    • Enterprise
    • Enterprise Plus:
      *Essentials Plus licensing is confusing because it technically does not include Storage vMotion, but it does include Enhanced vMotion, so you effectively get Storage vMotion functionality if you are satisfied with migrating a VM from Host A to Host B at the same time as migrating it from Datastore A to Datastore B.
This concludes part 1 of this article, please check back soon for the conclusion where 3 additional secrets will be revealed.