Taking VMware vSphere 5.5 for a Spin

by Paul Ferrill

Does the latest iteration of VMware's core offering deliver enough enhancements and new features to make it warrant a closer look?

VMware showcased their latest offerings at the VMworld event earlier this year, and one of the bigger announcements was for the latest release of the company's vSphere core offering, v5.5. We'll take a closer look at what the latest release has to offer as well as cover some of the new ancillary products associated with vSphere.

VMware vSphere 5.5 includes an upgrade to version 10 of the Virtual Machine hardware version. Enhancements in the 10.0 release include added support for LSI SAS controllers, new CPU architectures and a new advanced host controller interface (AHCI). VMware vSphere 5.5The AHCI support adds a new virtual SATA controller with the ability to attach up to 30 devices per controller and four controllers per VM. Do the math — that adds up to a whopping 120 disk devices attachable to a single VM!

Another highlight of the VMworld show was a focus on flash, both as a cache pool available to speed up a number of different VM functions and as a key piece of the new vSAN product. vSphere Flash Cache is shipping now as part of the vSphere 5.5 release and the vSAN product is available as a preview.


vCenter Server is the flagship management tool and takes on an even more important role with the 5.5 release. You'll need at least one instance of vCenter Server running to perform many of the new management functions.

While much of this functionality was available in the standalone vCenter client in version 5.1, that's all changed with version 5.5. The latest version of the vCenter Server Appliance (VSA) has been upgraded to increase its capacity with support for up to 100 hosts and 3000 virtual machines. That's up from 5 hosts and 50 virtual machines in the previous release.

vSphere replication adds the ability to perform point-in-time restorations. Previous versions of vSphere utilized a redo log to hold the changed blocks from the source host as an intermediate step before physically writing the snapshot to the target disk. Once the process completed, this redo log was discarded.

This two-step process kept a "last-known good snapshot" available in case of data corruption during the replication process. In version 5.5, these redo logs are maintained and periodically purged.

By default, the system maintains one snapshot per hour and provides an interface to pick a specific point-in-time snapshot to restore. A new Multi-Point-in-Time (MPIT) retention policy includes a number of user-configurable parameters to specify how often replications occur and how many to retain.


One of the big new features in the 5.5 release is vSphere Flash Read Cache. Architecturally, it is tied to the kernel, meaning control of available Flash Read Cache happens at a very low level.

This new resource is consumed and managed in the same way as CPU and memory in previous versions of vSphere. Functionally, it can be used as swap space for a Linux VM or as disk read cache to speed up I/O operations. Figure 1 shows where you configure this resource from the vSphere Web client on the settings page for an individual VM.

VMware vSphere 5.5 - Figure 1
Figure 1 (Click for larger image)

VMware vStorage APIs for Array Integration (VAAI) has been improved to include a new and simpler UNMAP command. This feature requires a storage array with UNMAP support and now works to reclaim unused dead space by specifying the size in blocks and in increments versus all at once. These two enhancements fix a problem that previously occurred due to a mismatch between the host and storage system with respect to the reporting of free space on thin-provisioned datastores.

VMware NSX

In the VMware networking space there's an entirely new product called NSX. At a very high level NSX is VMware's implementation of the software-defined networking (SDN) technology they acquired with the acquisition of Nicira.

This product is aimed squarely at service providers and large enterprises with complex networks. It utilizes STT and VXLAN tunneling protocols to encapsulate traffic and does it utilizing an in-kernel vSwitch. All that adds up to a flexible and high-performance network architecture to support very large networks.


The days of the full-featured Windows client are quickly coming to an end. vSphere version 5.5 does include an installer for the Windows client, but it does not support all the new features. For example, you can't edit the settings of a virtual machine running hardware version 10 from the vSphere client (see Figure 2).

VMware vSphere 5.5 - Figure 2
Figure 2 (Click for larger image)

That being said, you will find a number of improvements to both the vCenter Server Appliance (VSA) and the vSphere Web Client (VSC). The vSphere Web Client has seen much improvement and now includes drag-and-drop capabilities, a filtering feature for selecting objects based on specific criteria, and a recent items list to quickly navigate to commonly used objects.

For full-featured access you must install the VMware Client Integration Plug-in. At present this only exists for Windows users. The plugin is required for a number of functions, including accessing the client console, uploading VMware template files and more.

Once this plug-in has been installed you should have everything you need to manage your entire vSphere infrastructure. Figure 3 shows the new Recent Objects drop-down list for quick access to the most commonly used objects. The latest rendition of the vSphere Web Client is snappy and easy to navigate.

VMware vSphere 5.5 - Figure 3
Figure 3

Bottom Line

VMware continues to deliver incremental improvements to their flagship line along with new features like NSX, vSphere Flash Read Cache and vSAN. It remains to be seen if the switch to an all-web management interface will fly in the long term with the customer base. All in all, there are enough enhancements and new features to make this release worth a look.

Paul Ferrill, based in Chelsea, Alabama, has been writing about computers and software for almost 20 years. He has programmed in more languages than he cares to count, but now leans toward Visual Basic and C#.

Follow ServerWatch on Twitter and on Facebook

This article was originally published on Thursday Dec 12th 2013
Mobile Site | Full Site