Buying a new network-attached storage (NAS) as a storage appliance for your small and mid-sized business? You can check out my earlier blogs such as “Adopting a NAS Strategy for Your SMB” or “Other Features to Watch for in a NAS.”
For small businesses only interested in using their NAS for simple backups of business computers — and don’t really have time to delve into more complex capabilities — I’ve sketched out some quick pointers on what to look out for below.
Computing the Storage Capacity
Figuring out the raw capacity of NAS is a relatively simple affair, though putting a finger on the actual “usable” storage can be much trickier. To get the maximum capacity, simply multiply the number of hard disk drives (HDD) the NAS can accommodate with the largest capacity HDD that is supported — which should be 4TB at the moment. Of course, 4TB HDDs are still priced exorbitantly, so it may be wiser to settle for NAS with more drive bays for use with 3TB or even 2TB HDDs instead.
Actual usable storage is dependent on the level of redundancy that is configured. NAS with RAID 1, for example, will deliver half of your raw capacity as usable storage area, while RAID 5 with three disks delivers about two thirds of the raw capacity. Other storage schemes, such as Synology’s Hybrid RAID and Drobo’s BeyondRAID, work differently and are dependent on whether disk redundancy is set to “one” or “two” HDDs.
In general, you should subtract the size of your largest HDD away from your total capacity under a “basic” configuration; take away two of your largest HDD for a more conservative configuration.
Do note that some NASes can be upgraded to a higher capacity by means of a proprietary expansion chassis. Others may also support external HDDs via USB 2.0 or USB 3.0 ports, though it may pose a security risk for appliances that are deployed in an unsecured location.
Though some NAS and enclosures of late have started sporting wireless networking, wired connectivity is still the performance king by a wide margin. When selecting NAS with local area network (LAN) connectivity, note that fast Ethernet (100Mbps) is passé, and Gigabit Ethernet (1000Mbps) is really the minimum you should go for today.
Some NASes come with dual-Gigabit ports, which may support link aggregation or fail-over modes. The former allows you to increase the bandwidth by combining both network ports into one faster channel, while the latter allows you to survive the failure of one of the ports. Note that link-aggregation support must be present on your networking switch before it will work with your NAS.
Finally, some NASes come with 10Gbps Ethernet ports — or the ability to add 10Gbps adapters. They are priced on the higher-end of the scale though, and you really should read up a lot more than this blog if you want to commit to such a unit.
Though the above tips are relevant for both low-end to high-end storage appliances, it makes sense to more closely examine them for more advanced capabilities for more expensive units. Among others, some of these functions could range from cloud integration, replication to other NASes, and the ability to work with IP cameras.