VM-Centric Storage

We’ve designed Open vStorage to be VM-centric and a lot of the features we create over the next few months will leverage the VM-centric architecture. The idea of VM-centric storage has been implemented by new age storage companies such as Tintri, VMware (with vSAN) and us when designing our products.This approach is a huge departure from the “traditional” LUN based approach taken by SAN vendors. This brings the question – “What exactly do we mean by VM-centric architecture?”.

Managing VMs and not storage
The key feature with VM-centric storage is that IT administrators manage virtual machines and not storage. All storage actions are taken on a per virtual machine basis rather than having to understand LUNs, RAID groups, storage interfaces, etc. With Open vStorage any IT administrator having knowledge on managing virtual machines should be able to manage it rather than having to get into the complexities of storage and storage networking specifics. A simple example could be cloning. With Open vStorage an administrator can use a VM template to create clone(s) while a traditional storage administrator would need to clone a LUN and then export a particular VM to achieve the same result.

Storage Policies by Virtual Machines
VM-centric design allows for storage policies to be defined on a per virtual machine basis. A few examples of this is as follows:

  1. Replication from one storage cluster to another, can be done on a per virtual machine basis. Moreover, different replication schedules can be used for different virtual machines – as an administrator you may choose an important VM to be replicated every 30 minutes while a not so important VM to be replicated once a day. Moreover, different virtual machines could be replicated to different clusters.
  2. Data retention policies can be defined on a per virtual machine basis. Open vStorage takes snapshots of virtual machines every hour and soon we will be adding the capability whereby an administrator can set the retention policies for these snapshots differently for different virtual machines. For example for one virtual machine an administrator may set retention for 7 days while for another virtual machine it could be 3 years.
  3. With Open vStorage one can use multiple back-ends such as a NAS, file system, object store. We call these back-end storage systems as vPools. With Open vStorage one can have multiple such vPools per host. The administrator can then select vPool on which the data for a particular virtual machine is stored on again on a per virtual machine basis. Hence, an example would be a VM that needs fast I/O could use a vPool that provides fast throughput while a VM requiring not so fast I/O could be stored on a vPool that has a slower throughput.
    We feel that VM-centric storage is here to stay, and that over a period of time the idea of requiring separate storage management processes, software and people would become obsolete. Our engineers are not stopping at the above mentioned VM-centric features, and our key R&D staff are working on capabilities such as encryption (on a per VM basis), dynamic QoS (tuned per VM) and many more exciting innovations.
About the Author
Wim Provoost
Product Manager Open vStorage.