Storage DRS is a brand new feature of vSphere 5.0. It has been one of my focus areas for the last 6 months and probably one of the coolest features of vSphere 5.0. Storage DRS enables you to aggregate datastores in to a single object, called a datastore cluster. This new object is what you will be managing from now on. Storage DRS enables smart placement of virtual machines based on utilized diskspace, latency and LUN performance capabilities. In other words, when you create a new virtual machine you will select a Datastore Cluster instead of a Datastore and Storage DRS will place the virtual machine on one of the datastores in that datastore cluster. This is where the strength lies of Storage DRS, reducing operational effort associated with provisioning of virtual machines…
But that’s not all there is, Storage DRS is a lot more than just initial placement… lets sum the core functionality of Storage DRS up:
- Initial Placement
- Migration Recommendations (Manual / Fully Automated)
- Affinity Rules
- Maintenance Mode
These in my opinion are the 4 core pieces of functionality that Storage DRS provides. Initial placement as stated will reduce the amount of operational effort required to provision virtual machines. Storage DRS will figure out which datastore it should be placed on, no need anymore to manually monitor each datastore and figure out which one has the most available diskspace and relative low latency. On top of that SDRS also provides Migration Recommendations if and when thresholds are exceeded, it can generate them (manual mode) or generate and apply them (fully automated mode). These thresholds are utilized disk space(80%) and latency (15ms). This helps preventing bottlenecks in terms of disk space and hot spots in terms of latency.
Affinity Rules and Maintenance Mode are very similar to what DRS offers today. You have the ability to split disks and virtual machines with Affinity Rules, or keep them together. With Maintenance Mode it will be very easy to migrate to new LUNs or to do planned maintenance on a volume, couple of clicks and all VMs will be moved off.
Once again I would like to stress that although the Migration Recommendations (especially in Fully Automated mode) sound really sexy, and it is, it will more than likely be the Initial Placement recommendations where you will benefit the most. More technical information will follow soon here and on frankdenneman.nl