With data growing exponentially from one year to the next, the need for enterprise storage shows no signs of slowing down. However, figuring out what storage to buy can be a daunting process. Numerous vendors offer enterprise NAS devices, with various models available. This article will help users figure out what to look for when shopping for an enterprise NAS appliance.
NAS buying considerations
Let's examine some factors users should consider when evaluating NAS storage options.
Type of usage
One of the first things to consider when selecting a NAS appliance is how it will be used. Not all NAS appliances are suitable for enterprise use; many are designed specifically for consumer or small business use. Similarly, some systems are designed more for media streaming than for general use. As such, you'll need to consider your specific needs when selecting an appliance. A small business NAS may be fine for a remote or branch office, but it's probably not appropriate for an enterprise data center.
You can get a basic idea of the amount of storage space NAS systems provide by counting the number of drive bays. However, there are other factors to consider. For example, some appliances place limits on single drive capacity, meaning you can only install drives up to a certain size.
Some appliances contain additional storage options. For example, many appliances contain M.2 slots that can accommodate NVMe drives. Such slots are rarely included in the drive bay count.
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One more thing to keep in mind is that some manufacturers reserve drive bays for data caching. If, for example, a NAS appliance is designed primarily to work with HDD storage, the manufacturer may intend for a small number of drive bays to be used as an SSD cache. Cache storage isn't included in an appliance's usable capacity and reserving drive bays for cache storage reduces the number of bays that could be used for normal data storage.
In some ways, NAS performance is like PC performance. Faster processors and large amounts of memory generally equate to better overall performance. It's important to ensure the appliance can use error correction code (ECC) memory, which helps to reduce data integrity errors.
CPU and memory resources aren't the only factors that affect an appliance's performance. The type of disks supported also plays a big role. SSDs are faster than HDDs, but there's more to it than that. Some NAS appliances use SSDs to cache reads and writes to improve overall performance. From a performance standpoint, it's important to spread the cache across multiple SSDs because it enables the NAS to benefit from the combined performance of all the cache drives.
Network connectivity plays a huge role in overall NAS performance. Often, it's network connectivity -- not the NAS itself -- that limits overall performance. Simply put, a slow network connection can become a major bottleneck that limits appliance performance.
Nearly any NAS will include Gigabit Ethernet (GbE) ports. In some cases, these ports can be aggregated to enable them to collectively act as a multi-GbE port. It's preferable to use true high-speed connectivity rather than create a fast link out of several slow links. Having one or more 10 GbE ports is a good starting point, but some appliances support even faster links.
It's worth noting that nearly every NAS appliance contains USB 2.0 ports. These ports can sometimes be used to connect a keyboard and mouse, but they're usually used to attach external storage.
Most enterprise-grade appliances are designed to be rack mounted and adhere to 1U, 2U or 4U standards. Some NAS appliances aren't meant for rack use, however, making it necessary to verify an appliance's form factor prior to purchase.
Ease of use
NAS appliances use a built-in OS and a collection of integrated management tools. These resources are almost always proprietary, and some vendor's OSes and management tools are easier to use. When shopping for a NAS, ensure the appliance won't be excessively difficult to set up, manage and maintain.
NAS appliances almost always contain sensitive data. At a minimum, a strong encryption algorithm such as 256-bit Advanced Encryption Standard should be used to prevent data leakage if NAS drives are stolen. You should also look for other basic security standards such as HTTPS and multifactor authentication.
NAS reliability often comes down to the way NAS disks are configured using, for example, RAID 5, RAID 6 and hot spares.
Other factors that improve overall NAS reliability include the use of redundant hardware, such as redundant power supplies and network ports. Some NAS appliances also replicate data from one appliance to another to enable the secondary appliance to take over if the primary appliance fails. If you replicate data between appliances, it's essential to have a dedicated, high-speed link between the two appliances.
Most enterprise NAS appliances support remote management by way of an HTTPS interface. This typically means reserving one of the appliance's network adapters for management use and connecting it to your management network. This approach prevents management traffic from adversely affecting performance. It also improves security, since you won't be mixing management traffic and storage traffic on the same network.
Finally, before you select a NAS appliance you will need to check to see what types of drives it supports. Specifically, you will need to consider the following:
- form factor, such as 2.5-inch, 3.5-inch and M.2;
- type, such as SATA and SAS; and
- media type, such as SSD and HDD.
Beyond that, there may be capacity limits and support requirements to consider. Some vendors will only allow a certain capacity drive, for example, 10 TB or smaller. Similarly, a vendor may only support certain makes or models of drives. You might, for instance, be required to use Western Digital drives or risk voiding the appliance's warranty.
Enterprise NAS device vendors to consider
While there are numerous enterprise NAS devices available from vendors such as Dell EMC and HPE, this article focuses on options from lesser-known brands. Here are some of our top picks.
Like other vendors, QNAP offers a variety of enterprise-grade NAS appliances ranging from all-flash appliances to dual-controller NAS. One of the company's more capable NAS appliances is its TS-h3087XU-RP. This device is a rack-mounted NAS that supports up to 128 GB of DDR4 ECC memory and a mixture of HDD and SSD storage. QNAP recommends this NAS for tasks such as hosting VMs and containerized applications, backup repositories or cloud storage gateways.
QNAP offers the TS-h3087XU-RP in a variety of hardware configurations. It's equipped with an Intel Xeon E-2378 CPU running at up to 4.8 GHz. The appliance includes four slots for DDR4 ECC memory with each slot able to accommodate up to 32 GB. Other noteworthy hardware features include dual 10 GbE and 2.5 GbE connectivity, as well as redundant power supplies. The appliance features 24 3.5-inch SATA 6 Gbps bays for HDDs and six 2.5-inch SATA 6 Gbps SSD slots. Additionally, the appliance offers three PCIe 4.0 slots.
Synology offers several different NAS appliances, including all-flash arrays designed for scalability, and those meant for general-purpose storage. One of its more noteworthy NAS appliances is the RackStation RS4021xs+.
The RackStation RS4021xs+ delivers optimal performance and scalability. The rack-mounted appliance is equipped with an Intel Xeon D-1541, 8-core processor running at 2.1 GHz. It's natively equipped with 16 GB of DDR4 ECC RAM, but it can accommodate up to 64 GB in total. The appliance includes 16 drive bays supporting both 3.5-inch and 2.5-inch drives, but can be expanded to 40 drive bays through the use of the company's RX1217(RP) expansion unit. Additionally, the unit's two PCIe Gen3 slots can each accommodate an NVMe M.2 SSD for additional storage.
The RackStation was designed with data availability in mind. The appliance includes redundant power supplies and two appliances can be linked together to create a Synology High Availability cluster that supports minute-level failover times. Network connectivity is supported through four 1 GbE ports and two 10 GbE ports. The unit also features two InfiniBand ports.
Asustor offers a variety of NAS appliances, many of which are geared toward home office use. Such appliances are useful to those who wish to create a media server or personal cloud, or for those who simply need additional storage capacity and want to use something more sophisticated than a consumer-grade external hard drive. The company also offers several appliances for small businesses and at least one NAS suitable for larger organizations.
The Asustor NAS of choice for enterprise environments is the Lockerstor 16R Pro. This NAS appliance features a quad-core, 9th generation Xeon CPU and four DDR4 slots that can be filled with ECC RAM. The NAS comes with 8 GB of ECC RAM and can accommodate up to 128 GB. The unit features 16 drive bays, as well as two additional NVMe ports that can accommodate M.2 SSDs.
The Asustor natively includes four single GbE ports. Users requiring greater levels of throughput can take advantage of the appliance's two x4 PCIe slots and one x8 slot. These ports can be used to add SAS storage support and to install 10 GbE, 25 GbE, 40 GbE or 50 GbE network adapters.
TerraMaster also tends to focus primarily on home users and small businesses. The company does offer several enterprise-grade NAS appliances, such as the U24-722-2224, a 24-bay rack-mounted appliance.
The U24-722-2224 is equipped with a quad-core, 3.5 GHz Xeon processor (E-2224G). The appliance's four DDR4 slots come preconfigured with 16 GB of RAM but can accommodate up to 64 GB. The product's spec sheet doesn't indicate if ECC memory is supported.
The appliance has four single GbE ports, as well as three PCIe 3.0 8x expansion ports that can be used to install 10 GbE. Additionally, TerraMaster supports link aggregation for its built-in ports to enable greater throughput than what a single GbE port can provide. The link aggregation feature ensures the appliance can maintain network connectivity even if one port were to fail. In addition, reliability can be achieved through an optional redundant power supply and by combining two units into an active/passive cluster.
Check out these articles for more information on the pros and cons of NAS, deciding between a NAS or server as a storage option, and how to secure network storage.