8 NAS appliance features to consider for small business

NAS appliances designed for small to medium-sized businesses have become more feature-rich over the last several years. Below are eight key features to look for when purchasing a NAS for a small business.

1. Solid-state drive support. NAS vendors may support SSDs in several ways. Any appliance should be able to use SSDs for normal data storage. This practice is becoming far more common as SSDs become more affordable and offer higher storage capacities.

Additionally, some vendors design their NAS appliances primarily for HDDs, but include one or more drive bays specifically designed to accommodate SSDs for caching. For businesses to read hot data as quickly as possible, the appliance automatically transfers it to the SSD. Some vendors also use part of the SSD storage for caching write operations.

2. Flexible storage support. When contemplating a NAS for a small business, make sure the appliance is able to grow with the business. This means the organization should be able to use whatever drives they want, assuming the drives are physically able to connect to the appliance's storage controller. For example, if the company decides to upgrade to larger drives or make the switch to SSD storage, the appliance should allow for that.

3. Alerting mechanism. NAS appliances generally provide storage redundancy to prevent data loss in the event of a disk failure. Even so, the company needs a way to gauge the status of the disks within the NAS appliance.

Vendors take a variety of approaches to reporting on disk health. It's best to look for a product that conveys its health status through colored lights, email messages, sound or an integrated display. While web consoles generally work well, the storage administrator has to remember to periodically log into the console. Alerting mechanisms that do not require administrative effort tend to do a better job.

4. Supported protocols. Most NAS appliances geared toward the small business market support the CIFS and server message block. Some also support the Apple Filing Protocol and the iSCSI protocol.

Companies should determine which protocols their appliance will need to support before they start shopping, as the protocol support will determine how to use the appliance. An appliance with legacy SMB support will not support some of the more modern Windows Server features. Hyper-V Virtual Machine Storage, for example, is only supported on server message block 3.0.

5. Thin provisioning. Depending on how the organization plans to use the NAS appliance, thin provisioning may or may not be an important feature. If the plan is to configure the NAS appliance as a file server, thin provisioning probably isn't necessary. If the company plans to create a number of different volumes on the appliance, thin provisioning can be helpful.

With thin provisioning, a volume consumes storage space only as needed. Take, for example, a thinly provisioned 40 GB volume: Although the OS treats this volume as a bona fide 40 GB volume, it will initially consume less than 1 GB of physical disk space. It only consumes additional storage space when data is written to the volume. The advantage to thin provisioning volumes is it allows a company to create volumes large enough to accommodate future data growth without consuming physical storage unnecessarily.

6. Support for mixed drive sizes. It may be easy to initially dismiss this feature as being unimportant, but there is at least one reason why a NAS for a small business needs to support the use of mixed disks.

Imagine, for a moment, that a company purchases a NAS appliance and installs 1 TB disks into each of the drive bays. The company also decides it needs protection against physical disk failure, so it configures the appliance as a RAID 5 array. A few years later, one of the disks in the appliance fails. The company gets ready to replace the disk only to discover that vendors no longer sell 1 TB drives.

If the NAS appliance does not allow mixing disk sizes, the company will have to figure out a way to offload all the data from the appliance before another disk fails and then incur the expense of replacing every disk in the appliance with whatever disk size is available. Moral of the story: Buying an appliance that supports mixed disk sizes can potentially save a lot of money and frustration later.

7. Flexible data protection. All administrators seem to have their own ideas about how to configure storage. Some attempt to achieve the best performance, while others use a configuration that will provide the best protection for their data. And others use a storage configuration that falls somewhere in the middle. An organization should ensure its NAS appliance offers a high degree of flexibility with regard to the storage architectures it supports.

Some lower-end NAS appliances only support mirroring. Others support RAID 1 and RAID 5, but nothing else. A good NAS appliance should give a company the freedom to choose the storage architecture. The better NAS appliances support RAID 0, RAID 1, three-way mirroring, RAID 5, RAID 6, RAID 10 and possibly even some of the more exotic storage architectures. Some provide the option of designating a disk as a hot spare that can take over in the event of a disk failure. The number of drive bays in the appliance plays a major role in the storage architectures supported.

8. Built-in battery backup. An unexpected power loss can cause the data in a NAS appliance to become corrupted. Data striped across multiple disks increases the risk. Some vendors build a backup battery into their appliances as a way of preventing data loss during power outages. If a company's NAS for small business purchase does not include a backup battery, the company should make sure to budget for an uninterruptible power supply.

As shown, there are several features to consider when shopping for a NAS appliance for a small business environment. There are also major differences between the various NAS vendor offerings, so it is important to take the time to choose an appliance that will meet the company's needs.