vSphere 5 Profile-Driven Storage: Get VM Placement Right the First Time
We all get in a hurry. When we get in a hurry we make mistakes. The following scenario has been played out plenty of times in a virtual infrastructure.
- VM Administrator gets a request for a new VM to be deployed ASAP, which usually means yesterday.
- VM Administrator looks through multiple datastores to determine a datastore with a sufficient amount of capacity.
- VM Administrator picks the datastore and deploys the VM.
What if this particular VM was a database server and the log volume needed to be provisioned on a RAID1/10 datastore. Hopefully the datastores are named with the RAID level in the naming convention. But, what if they are not? Even if they are, it can be very tedious to wade through multiple datastores to find an appropriate datastore that meets both capacity and performance requirements. What if there was a way to “tag” certain datastores with characteristics that are meaningful to the VM administrator? That’s where the new “Profile-Driven Storage” feature comes in with vSphere 5.
Profile-Driven Storage allows user-defined “tags” and automated storage property discovery through the vStorage API’s for Array Awareness (VASA). Let’s take a look at the user-defined “tags” first.
User-Defined Storage Profiles
Very simply, the user-defined “tags” allow one to “tag” a datastore with meaningful text. In the example above, we could define an appropriate datastore as “RAID 1” in the datastore’s storage profile. Then, when the VM administrator provisions the VM, he or she simply selects the “RAID 1” storage profile as being applicable to the VM that is being provisioned. This ensures that the VM will be placed on an appropriate datastore because only those datastores that fit the “RAID 1” storage profile will be available as choices during the provisioning process. If more than one virtual hard drive will be in the VM then multiple storage profiles can be used. For example, you could use a “RAID 1” profile for one virtual disk and a “RAID 5” profile for another virtual disk.” The storage profiles ensure compliance and make it easier for the VM administrator to provision a new VM without human error.
VASA Storage Profiles
Arrays that can take advantage of VASA can provide storage characteristics for the VM administrator. Examples might be RAID Level, Deduplication, Replication, etc. One of these characteristics can be assigned by the system to the storage profile. This further eliminates human error and helps to ensure compliance during and after provisioning.
As you can see, Profile-Driven Storage ensures that VM’s get provisioned correctly the first time. No need to Storage vMotion the virtual machines around after the fact unless their storage requirements need to change. The above is a very simple example of what can be done with Profile-Driven Storage in vSphere 5. Profile-Driven Storage is flexible enough to fit many different use cases. It’s up to you VM admins out there to fit it to your particular use case.