Wouldn’t it be nice to use a storage array’s tools to manage a virtual machine’s storage, especially if it was as easy as connecting it to your virtual machine (VM) using an API? That’s exactly how the Platform9 Private Cloud Director, the best VMware alternative, approaches storage.
Let’s review what we’ve always done with VMware, and see how the Private Cloud Director solution makes life easy for vAdmins and storage admins alike.
VMware’s datastore architecture
If you’ve been a VMadmin for any time, you’ve created many hundreds (thousands!) of virtual machines, without thinking about the required storage. That is, until the datastore ran out of space. Even then, you probably just put in a ticket to your storage admin requesting more storage.
VMs are created inside a datastore. A datastore is created by formatting a single disk on the ESXi host or an attached storage volume with VMFS (VMware file system). In the case of a datastore on attached storage, multiple ESXi hosts can be connected to the same LUN. Every host stores its virtual machine files in its own subdirectory on the VMFS, and every host can see the entire LUN.
One of the benefits to this architecture is that you don’t need to be a storage administrator to manage the attached storage. You simply let the storage administrator know how much space is required, make sure the host can see the LUN, and format the LUN with VMFS. The datastore method also makes it easy to manage the performance of groups of machines and their storage utilization.
The disadvantage of the datastore architecture is that if the storage array goes down, so does the datastore, taking all the VMs with it. Also, if one VM gets busy, it could become a “noisy neighbor” to the other VMs on the datastore. You also are unable to take advantage of the management features of the storage platform.
Other storage method used by VMware
As storage vendors improved their storage management methods, and customers wanted finer control of the storage provided to VMs, vSphere introduced vVols (Virtual Volumes). vVols allow storage management at the individual VM level by leveraging array-based data services. The storage hardware must support the VASA (vStorage APIs for Storage Awareness) APIs.
vVols enables storage management at the VM level, enabling granular control and policy-based provisioning. It offloads storage operations such as snapshots, cloning, encryption, and Storage DRS to the storage hardware. This leads to better resource utilization, because the load on the ESXi host is reduced.
There are some disadvantages. vVols is a 100% VMware solution, and using them will lock you in even further. Storage providers are responsible for their code, so hopefully your storage provider is on the vVol train, and backup provider support has been spotty.
Private Cloud Director and storage
It’s been a decade since VMware released vVols. Today, you have a choice for what hypervisor you trust to run your workloads. Platform9 Private Cloud Director provides what you need in an agile private cloud, including ways to use your preferred storage array and its management tools. There are two types of storage for the Platform9 Private Cloud Director platform. Let’s explore.
Ephemeral storage
Ephemeral storage is used to run a VM’s operating system and scratch space. It is temporary and non-persistent. It is used with stateless applications that can tolerate individual VM failures, but need to be deployed or reimaged quickly.
Ephemeral disks are usually created using the direct-attached storage of the hypervisor server, and the Private Cloud Director Compute Service manages them. An administrator configures the size of the VM when choosing the “VM flavor”. When the VM is destroyed, the ephemeral disk (VM root disk) is also eliminated.
Cloud native applications are a great use case for ephemeral storage. As a cloud workload scales down, the compute capacity of the VM is no longer needed. The expectation is that the data doesn’t need to persist beyond the life of the VM. This agile approach ensures efficient use of underlying hardware resources in an environment where workloads are composed and torn down continuously.
Enterprise Block Storage
Private Cloud Director also uses block storage. It is used for workloads that require persistent data. It’s very easy to set up storage for your VMs on Private Cloud Director during cluster blueprint creation. Cluster blueprints are declarative and descriptive.
Setting up storage is simple. Private Cloud Director provides out of the box configuration for a few storage systems, but supports a larger, more comprehensive list. Configuration is easy, just enable the storage system of your choice. If the one your organization uses is not on the list, you just need to supply the required access information via key-value pairs.
You’ll never need to request a storage administrator to carve up a huge LUN for you to turn into a datastore. Instead, each time you create a VM, you’ll create a new volume on the storage array. Your VM will be directly mapped to the storage.
This may make you, and perhaps your storage administrator, nervous. After all, it’s a new approach. Read on for why this is a good change.
Enhancing VM Storage with Private Cloud Director’s open approach
The Private Cloud Director approach to persistent storage is similar to VMware vVOLs. However, the open approach Private Cloud Director uses allows you to quickly attach the storage of your choice to hypervisor clusters, providing flexibility and avoiding vendor lock-in.
This open approach allows you to finely tune storage management per VM. Private Cloud Director allows you to attach different storage volume types to the same hypervisor cluster. This means VMs can access the type of storage volume that is best for the business use case for that VM. You can even attach volumes from different storage vendors. That’s hard to do using a monolithic datastore.
You don’t have to worry about losing the VMware features you need to use. Many of these are now offloaded to the storage management system, something you may have heard from your storage administrator. Common features that storage management can pick up are storage-side deduplication and global copy-on-write snapshots. Allowing the storage to handle storage management tasks frees up resources on the server side for other tasks
Even VM migration (known as vMotion in vParlance) is available on Private Cloud Director. Storage live migration is also available. It’s as easy as choosing the “Retype” option in the Private Cloud Director Volumes tab to move a volume from one type of storage to another. That’s really all there is to it.
Take the next step
Like what you hear about Private Cloud Director’s storage capabilities? Take the next step with a proof of concept with Platform9’s community edition, and contact our sales team to get all your questions answered. Once you experience the ease of migration and management, we think you’ll quickly conclude that Private Cloud Director is the right choice for modern private cloud management.
