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Storage area networks were once limited to large organizations with the resources to deploy and maintain these complex systems. Prices have decreased, however, and SANs have become a viable option for small and medium-sized businesses, especially those that manage large amounts of data or run applications with high-performance requirements.
Even so, SMBs shouldn't rush to abandon network-attached storage just because of the increased availability of SANs. They should first evaluate their current storage systems and look for these seven signs that it's time to move from NAS to SAN.
1. The NAS system cannot deliver the necessary performance
If the current NAS system can no longer deliver the performance necessary to meet user and application requirements, it's time to consider a SAN. Storage area networks typically offer much better performance than NAS. They are usually based on Fibre Channel (FC) or iSCSI infrastructure, which offer high throughputs and low latency. Currently, the FC interface can support speeds up to 128 Gbps and will get faster, with iSCSI networks not far behind.
Ethernet technologies are also getting faster, but a SAN is usually separate from the primary LAN, which provides a dedicated infrastructure solely for storage. In this way, storage traffic has all the available network resources and doesn't compete with the everyday congestion that can fill a LAN. In addition, FC networks make extensive use of host bus adapters (HBAs), which offload network processing from the server CPUs. That process improves storage performance.
2. Changing workloads require greater scalability
As organizations manage more data and run more high-performance applications, they must also contend with -- and accommodate -- shifting workload requirements. To support these workloads, organizations need storage systems that can easily scale to meet changing conditions. Although some NAS systems support scale-up or scale-out capabilities, many have fixed configurations, especially lower-end products.
Scalability is one of the primary reasons organizations move from NAS to SAN. SMBs might want the ability to easily add capacity or boost performance as their companies grow. To scale entry-level SAN storage, they only need to add the necessary switches and disk space. Although a SAN can scale to thousands of disks, most SMBs will likely need far less. The biggest constraint on scaling is often the cost.
3. Availability and reliability issues are on the rise
Few organizations can afford to have their storage systems go down unexpectedly. NAS systems, particularly entry-level products, often have one or more single points of failure. If one of these components goes down, supported applications and workloads do as well, which affects productivity. Even NAS systems with redundant components, such as power supplies, struggle to compete with SANs for availability and reliability -- capabilities inherent in the SAN architecture.
Organizations that experience availability issues with their current systems should seriously consider a move from NAS to SAN. A SAN is made up of computers and storage devices interconnected by multiple switches. It is designed for mission-critical workloads and includes numerous redundancy levels, along with failover capabilities. For example, if a switch or server fails, the SAN can automatically reroute storage traffic to avoid service disruptions.
4. The NAS system doesn't meet data protection requirements
Data protection has become a growing concern for organizations of all sizes, including SMBs. Data loss weakens productivity and tarnishes a company's reputation. It can also have serious consequences regarding compliance regulations, which govern both data protection and retention. Some NAS products support enough disks to implement a RAID configuration, but usually not lower-end systems.
An SMB doesn't necessarily need a SAN to meet data protection requirements. However, a SAN can deliver this protection because it treats storage as a collective resource that's centrally organized and managed. In this way, administrators can maintain their storage devices as a unified system, which makes it easier to replicate and protect the data. The system offers disaster recovery and achieves regulatory compliance. A SAN also provides data redundancy through techniques such as backups, snapshots and storage cloning.
5. The NAS system doesn't meet workload and application requirements
SMBs might discover that NAS systems can no longer support their workloads and applications. For example, an SMB that runs a small SQL Server implementation on a NAS system might have a growing user base and increased amounts of data, along with more powerful applications. That evolution makes it difficult for the database system to keep up with demand.
Typically, a NAS provides file-based storage and a SAN provides block-based storage. Software such as database management systems often requires block-level storage to operate at an optimal level. In addition, many mission-critical workloads demand the performance, availability and data protections that SANs offer. For example, a SAN can benefit workloads such as email servers, CRM systems or collaborative video editing that involves large files.
6. Virtualization deployments require better storage
Some NAS systems, especially higher-end products, support virtualization. However, an SMB that relies on server virtualization or virtual desktop infrastructure (VDI) will likely operate better with a SAN, especially as those workloads continue to grow.
Virtualization, whether server virtualization or VDI, puts a significant demand on storage resources and will often perform better within a SAN environment. The SAN platform can maximize performance and availability to meet the needs of the virtual servers or desktops. A SAN also provides the virtualization platform with direct access to block-level storage, which optimizes performance. An FC-based SAN increases a server's VM density by offloading network processing to the HBAs.
7. There's a growing need to consolidate and better use resources
Midmarket and high-end NAS products consolidate multiple file servers. Administrators can also cluster high-end NAS systems. For some SMBs, however, this platform might not be enough. For example, if an SMB runs multiple low-end or midmarket NAS systems, the company could end up with numerous data silos, which complicates data management and increases security and compliance risks. Siloed storage also leads to poorer resource utilization.
A SAN enables admins to collectively provision, control and protect a system. It consolidates storage and improves resource utilization. It also lets an organization deploy servers where needed. In this way, administrators have a single, consolidated system that avoids silos and collects the storage within a common management framework.