So you’ve decided to virtualize your storage. Virtualization often means dealing with complex shared storage for the first time. For example, a SAN configuration may require an FC Switch, a Server HBA, FC cables, and an external RAID storage hardware. Its complex, it takes up space, and it isn’t very efficient.
What if there was another option available? One that allowed to you create a software-based shared storage solution that acted like a SAN and not like a traditional Virtual SAN Appliance?
This solution is closer to reality than you may think.
At VMware Partner Exchange, VMware unveiled their forward-looking solution called VSA to solve the problem of costly, complex storage solutions. Other industry terms for this are distributed storage, unified storage, and software-defined storage.
What is a VSA?
In the future, with a VSA (Virtual SAN Appliance), you will take the local hard drive on the server (often a cluster of 3) and the VSA copies information across servers. Then, software pools all of those hard drives together to act as a single storage array. This isn’t magic, it’s software-defined storage, and it’s made up of 3 main components:
- Storage Policy based Management
- Virtual volumes, virtual flash and virtual data services to enhance traditional storage
- Distributed storage to enable scale out Direct-Attached Storage (DAS) for vSphere
Bewitched? If you want to learn more about the concept behind a Software-Defined Data Center, check out our previous post The Software-Defined-Data-Center (SDDC): Concept or Reality?
Who is it for?
VMware says that “VMware vSphere Storage Appliance (VSA) transforms the local storage within your servers into a shared storage resource that runs your virtualized applications.” Accordingly, I feel a company with the following profile is ideally suited for this solution:
- Many locations with a small IT staff
- An SMB starting to virtualize
- Plans for expansion i.e. building a new location and want to manage the location remotely
It’s good to know this solution is aligned with T10 industry standardization. This is important because almost all modern IO interfaces use the iSCSI architecture. Although it sounds like an enterprise solution, I think it has an immediate payout to the SMB space by reducing initial costs for hardware to support an intelligent storage environment. This is a great alternative if you can’t afford a Storage Array Network or if you want to start virtualizing and don’t have the budget.
How does it work?
Building out a separate network for storage can be complex and expensive. If you do not have the right skills available in house, you will need to engage external professional services. In addition, managing a SAN requires specific knowledge to operate and keep optimized. The cost and complexity may outweigh the benefits.
With the VSA or software-defined storage, local storage on your servers is shared across all servers. Then, software intelligently places storage information on those hard drives by tiering your storage on the SSDs and HDDs. It’s tightly integrated with other vSphere functions. IO boot is directly tied in, and it runs on every single host in the cluster. Again, it uses local attached disks and SSDs on hosts.
In short, it provides a converged platform for storage and compute on the same server. This minimizes the use of memory and CPU for storage overhead.
Primary Use Cases:
- VDI – built in caching to deliver high performance and avoid boot storms
- Tier 2 or 3 workloads and testing or dev environments that demand fast provisioning at low cost
- Big Data environments that need scalability and high bandwidth
- Disaster Recovery where you want reduced hardware at a remote site
All it takes is turning on VSAN and adding it to the cluster, and the technology does the rest. For example, you provision a new VM, that requires ‘X’ capacity, ‘X’ amount of IOPs, and specify the kind of RTO/RPO. Essentially you can take policies and translate it down to a storage policy area.
Is software-defined storage the best path for all storage in the future?
It does seem like this concept reduces costs and simplifies management. This means better ROI when your storage is better utilized locally. However, remember that your storage solution needs to serve your business first, and not the latest industry trends. For example, you can set up tiered storage in your SAN to manage storage drives. With a VSA software tiers it for you on those local drives in the server. So you can compare solutions all day, in the end you need to choose what fits your IT environment and your budget.
Can I buy the VSA today?
It is not available today, but VMware has provided key partners like Softchoice a tech preview of the technology. I am looking forward to see how the final product operates and the use cases that it will address. My advice is that, depending on your organization and what you need, this may be a good option in the future when it becomes available.
Is this something you would adopt? What questions do you have? Let me know in the comments below and I’ll respond as soon as I can.