It used to be that only large companies found the need for a reliable centralized data storage in their office network. But as digital content such as movies, music and software became more accessible, this necessity for network attached storage (NAS) devices has made its way to home users and small offices. With so many brands and models to choose from, you can be sure to find a NAS with the right capacity, throughput and reliability to suit your needs.
Types of NAS
Built-in drive NAS
If you want to be rid of the task of scouting for individual drives for your network storage, then you'll probably end up with a built-in drive NAS. It's got everything in one package and all you'll have to do is hook it up to your network. The downside, however, is that its parts are most likely exclusively compatible with each other. While you can be confident that the NAS and the disk drive will work harmoniously, in the event that you have to replace a faulty drive, you'll have to request for a spare from the manufacturer, which may cost time and money.
Though they require some technical know-how, custom-built NAS devices will give you the freedom and flexibility in terms of budget, capacity and performance. Unlike the built-in drive type, you're not limited to the hard drives that already came with the package. Instead, you'll get a case with all its circuitry, which you'll have to fill up with compatible drives of your choice. A bit of a gamble? Yes. But a risk worth taking, nonetheless.
How to Choose a NAS device
Knowing the right storage capacity for your network is definitely the most crucial decision in choosing a NAS device. Most home users may find a 1TB NAS sufficient while large networks will require tenfold or more depending on its nature. Your decision should not only lie on the initial storage size; you should also consider expansion and backup. Thankfully, most brands these days allow you to expand your storage space. The question, then, is how. Multi-drive NAS have two or more slots where you can always freely add an internal drive to increase the capacity. There are also models that allow you to create virtual drives with iSCSI support.
NAS devices have little computers that allow them to systematically group data into sets so that users can easily access, alter or backup files. This process is called Redundancy Array of Inexpensive / Independent Disks or RAID. RAID NAS usually have two to four drives at the minimum and depending on its RAID type, a NAS device can be geared towards performance, reliability, or both. RAID 0 requires at least two drives and focuses on speed of transmission through disk "striping". This means that they are distributed in chunks to each of the physical drives with each one capable of storage and transmission. However, it doesn't allow any space for redundancy or backup which means this type can not be used on critical systems. Another common type is RAID 1 or disk "mirroring". This process also needs at least two drives to accomplish, however, in RAID 1 mode, the NAS has to duplicate every single data and write it on all the physical drives available, therefore taking up more space and making it slower than RAID 0. On the flip side, it offers fast read operations and uninterrupted connection even if one of your drives fails. If you're looking for a balance between performance and reliability, then you should buy a RAID-5 capable NAS with at least three drives. It's the most common operation used in NAS devices for the exact same reason. Like RAID 0, it implements disk striping, however, RAID 5 allots one stripe in each drive to store parity information which gives the NAS tolerance for, at most, one drive failure. There's also RAID 10 which may seem like an upgraded RAID 5 in terms of throughput and reliability and is becoming the trend among high-end NAS. The rest of the types (RAID 2-4, 6-9) are simply seldom used these days because they're either obsolete or riddled with performance issues.
HDD form factor
If you decide to go for a multi-drive NAS device or if you already have one and are looking to expand your storage space, then you're next concern should be the HDD form factor. It's an industry standard referring to the external dimensions of a hard disk drive. The most common ones are the 3.5" and the 2.5" form factors. But don't be surprised if the sales clerk hands you a 4-inch wide hard disk when you've asked for a 3.5". The figure is just a guide referring to the platter size of the hard drive dock where it will fit; not the exact width of the hard drive itself.
Connectivity and Features
There are still many NAS that support 10/100 Ethernet connection, but soon enough, the faster Gigabit Ethernet transmission will become the standard. Pick the latter only if you expect a lot of large-file transfers in your network. If you intend to produce hard copies of your network files, then you may want to find a NAS model that has USB 2.0 docks or higher with printer support. Some variants can also be connected to IP surveillance cameras or act as a multimedia server.
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