Storage as a service aims to simplify management by outsourcing administration to the vendor and making procurement similar to purchasing public cloud storage. This type of infrastructure is a hot trend but it's still an emerging market. So, it's important to ask the right storage-as-a-service questions before buying.
There are major differences when buying storage as a service, as opposed to on-premises hardware. Buying a service can speed the time to delivery, and it can shift the financial model to the same type of Opex spending associated with the cloud. Organizations often choose storage as a service to set up a "cloudlike" experience in buying and managing storage.
However, some of the terms and concepts -- such as buy vs. lease and subscription vs. consumption pricing -- may cause confusion if they are unfamiliar to infrastructure buyers.
Should I buy a service or lease?
Many IT buyers are familiar with leasing, which enables customers to use storage without having to own equipment that often needs replacing in three to five years. There are some similarities with buying storage as a service; however, there are key distinctions as well.
- Leasing includes a fixed contract term.
- The vendor owns the infrastructure; there are provisions to return or buy the equipment at the end of the lease.
- The price is calculated based on the value of the infrastructure.
- Leasing usually includes a fixed monthly payment.
- Typically, it does not involve service-level agreements (SLAs) or service-level objectives (SLOs), which demand the vendor live up to performance and availability metrics.
- A customer is usually required to handle management, monitoring, system updates, patches and support.
With buying storage as a service:
- Buying includes a fixed contract term.
- The vendor owns the infrastructure.
- The price is calculated based on the value of the service the vendor provides.
- Purchases may be a consumption model that can cause monthly payments to go up or down.
- Buying usually involves SLAs or SLOs.
- The vendor is usually required to handle management, monitoring, system updates, patches and support, especially if it is a managed service.
Am I buying products or buying outcomes?
Buying on-premises storage hardware or software requires the customer to become familiar with vendor brands, whether they are looking for block storage, file storage, object storage or unified systems. These vendor products are usually broken down into entry, midrange and high-end platforms as well, with various performance and scaling requirements. Doing proper homework -- including proof-of-concept testing -- helps the customer know what to expect when the system is delivered.
When buying services, however, the customer often buys outcomes. Instead of purchasing a specific vendor brand and model, the customer may choose service delivery levels. They include the following:
- storage type (block, file, object);
- performance tier (all-flash, HDD, hybrid);
- capacity; and
- subscription term (usually, one to five years).
The vendor then determines what configuration and infrastructure best meet the customer needs. The customer doesn't know the product brand and model unless it requests that information. The customer then manages the storage through the vendor's portal, rather than an interface designed for a specific storage system.
Know upfront who is responsible for what services. Responsibility for areas such as data protection, replication and migration may not be so obvious when buying primary storage services.
What are the differences between SLAs and SLOs?
Public cloud customers are familiar with SLAs -- they are commitments to system availability levels. It's the same with storage vendors. The vendors usually commit to a percentage of uptime, and customers receive credits or other compensation if the vendor fails to meet the commitment.
SLOs are performance metrics measured by IOPS and read/write throughput. Organizations can use SLOs to determine if a service is considered a performance or basic tier, for example. As with SLAs, customers should expect remuneration from the vendor if SLOs aren't met. But vendors don't always offer compensation for not meeting SLOs, so make sure it's clear what will happen if they fall short.
Is there subscription or consumption pricing -- or both?
Subscription pricing is a familiar concept, but it's often combined with consumption pricing when buying storage-as-a-service capacity. The subscription includes a term and a base level of capacity. Consumption pricing is the fee charged for capacity beyond the base subscription rate. Monitor capacity usage, and understand how data reduction technologies affect the pricing.
Is it a managed service?
Not all storage services are managed services. A managed service means the vendor is responsible for delivering, installing, integrating, testing, supporting and upgrading the storage system. On-premises storage as a service requires the customer to do all or many of those functions.
When replacing an on-premises SAN or NAS, there are other issues to look at besides storage types and capacity. For instance, does the service include direct connection to public clouds and management of data in the cloud? What are the network characteristics or requirements, and are they included in the service?
While data protection and DR are often sold as standalone services, they are likely an add-on to primary storage services. Is any protection included in the service, and who is responsible for backing up, archiving and migrating data?