• 07/29/2010
    2:17 PM
  • Rating: 
    0 votes
    Vote up!
    Vote down!

Network-Attached Storage User's Guide

Features on the latest NAS devices transform them into full-featured, multi-purpose computing devices which can act as media, print, and file servers, surveillance devices, and Web hosts.

Network Attached Storage Users Guide
(click image for larger view)
Buffalo TeraStation Duo
Once you have an estimate of your expected storage requirements, double it. That's not necessarily because your initial estimate was wrong, but rather because you'll likely want to employ one of the data protection practices known as RAID, or redundant array of independent disks.

If you simply copy your files to an external hard drive and then delete the originals, you're gambling that the external hard drive won't fail. Over time, you'll lose that gamble. By contrast, if you use disk mirroring (RAID1) or disk striping (RAID5) to store your data across multiple drives, a single disk failure isn't a disaster, but instead an advance warning to install a new drive.

Accordingly, I would recommend a dual-bay NAS device for RAID1 disk mirroring as a minimum specification for anyone considering this technology. This means that if you need 1 TB of storage, look for a 2-TB NAS solution supporting two separate 1-TB drives.

While it may seem extravagant to purchase twice the hard drive capacity than you expect to need, just remember that for every gigabyte of RAID-protected data moved to your NAS, that's a gigabyte you can delete from your PC's primary hard drive, freeing up space for easier defragmentation and better performance. Your laptop's hard drive should be a digital briefcase for the files you're working on now, not a digital safe deposit box containing everything you've ever done.

Starting with RAID1 on your NAS, you can safely delete files on your PC, and then more easily upgrade operating systems, try new applications, or download new content without worrying about disk space. It's a liberating experience.

Although RAID5 costs more to implement up-front and has performance disadvantages relative to RAID1, it provides higher levels of data protection and becomes quite cost-effective for larger implementations. Here are some sample calculations comparing the QNAP TS-210 two-bay (using RAID1) with the QNAP TS-410 four-bay NAS (using both RAID1 and RAID5), with 1-TB and 2-TB Western Digital Caviar Green hard drives:

NAS Hard Drives RAID TB Available Street Price Cost per TB
QNAP TS-210 2x1TB Level 1 1 TB $420 $420
QNAP TS-210 2x2TB Level 1 2 TB $540 $270
QNAP TS-410 4x1TB Level 1 2 TB $720 $240
QNAP TS-410 4x1TB Level 5 3 TB $720 $240
QNAP TS-410 4x2TB Level 1 4 TB $960 $240
QNAP TS-410 4x2TB Level 5 6 TB $960 $160

Prices vary widely by manufacturer and disk size, but the basic math points to buying the largest available hard drives that fit in a given unit. While RAID5 is less expensive as storage needs increase (not including the higher power usage), it's most appropriate for read-only applications such as media servers. If you expect to use your hard drive capacity for write-intensive applications such as content generation, file downloading, or database access, RAID1 may be a better fit.

Many vendors, mainly traditional storage companies such as Buffalo, Iomega, and Seagate, provide NAS devices with pre-installed hard drives. Other vendors, such as QNAP, Synology, and Thecus, require you to purchase and install hard drives from a list of compatible devices. That aspect shouldn't put you off much, since NAS devices have been designed to make it easy to install or replace hard drives.

We welcome your comments on this topic on our social media channels, or [contact us directly] with questions about the site.

Log in or Register to post comments