vCD or VDC. That is the question. Bit of dyslexic’s nightmare this blog post. vCD = vCloud Director (product) and vDC (Virtual Datacenter) an object within vCloud Director.
One critical piece of the vCloud Suite is vCloud Director 5.1. Yes, there’s a number changing to bring the product in line with the number of all the products in the suite. There are range of enhancements and changes that are worthy of note, but let’s start with the easy consume stuff.
Snapshots
vCD 5.1 now support snapshots for all the main functions such as create, revert and delete (or commit as some people prefer to say). They can be applied to individual VMs or applied to an entire vApp. As you would expect there is a graphical UI, as well as REST API. The support for snapshots also allows to snapshot used to be audited on with Chargeback. After all nothing is for free – and snapshot to consume disk space over time. When a snapshot is enabled you will see a green “tick” in the vCD web-pages, also you will find that your network settings are “dimmed”. That’s because your network settings are not captured as part of the snapshot. Also when you snapshot a vApp it doesn’t snapshot your vApp settings. This means you can make changes to your vApp settings, and have those preserved even if you revert the state of the VMs within the vApp. At the moment that snapshot level is just one at the moment.
Storage & Storage Profiles
In the past a Provider VDC was only able to offer one class of storage – this wasn’t as flexible as was first hoped. So with vCD 5.1 one Provider vDC can now support multiple tiers of storage. This should hopefully help aligning a VM or vApp with the right tier of storage given the demands of performance, capacity or cost. This extends not just the first class citizen of vCD but to ancillary storage requirements such as templates and isos.
On top of this vCD is now “Storage Profile” aware. Storage Profiles was a new feature in vSphere5.0, and wrote extensively about in my days at RTFM. Basically, its away of classifying your storage either by the administrator defining profiles or in more sophisticated way – using your storage vendors “VASA” provider that can actually interrogate the storage and classify it for you – giving you the attributes you need to create your profiles – so typically the VASA provider might work out – the RAID level, Disk Type and Replication status. This would allow you to create a storage profile that only included datastores that were on RAID10, SAS and Replicated as opposed to RAID5, SATA and not replicated. Essentially, storage profiles (when they are used with vSphere5.x alone) to provide an alternatively to just a list of datastore (or datastore clusters) and volume label – it kind of filters the user to select the right type of storage for the right type of VM or vApp. Now that storage profile goodness is exposed up to vCloud Director. vCD is also SDRS aware – which means SDRS can move a VM from one datastore to another to improve its performance – so long as it the destination maintains the same profile, and as consequence the same quality of service/experience.
Provider VDC spans Clusters
One of the improvements that caught my eye was change in the way the Provider VDC access resources. It’s now possible for vCD to have more than one cluster backing a Provider VDC. An “intelligent placement engine” then takes control of placing the VM on the right cluster to service its needs. For me this important because vCD is steadily removing the boundaries that exist with vCenter – and side-stepping any of the configuration maximums at the virtualization level such as the maximum number of ESX hosts in cluster.