In need of some network storage in the home ? Well, you could go off and buy a proper NAS unit, offering RAID, several Tb of storage, fast access speeds and so on. On the other hand, you might have something lying round the house that will do. It won’t be as good as a proper NAS, but it might just be good enough.
Many devices, while designed for a specific use, also have NAS functionality built in. A kind of fringe benefit. Just add an external disk and away you go. There are a couple of drawbacks, mainly speed. Generally, these systems employ low power CPUs that will naturally limit the rate of data throughput. So, they are not suitable for backing up large amounts of data on a regular basis. But streaming video, playing MP3s, casual file sharing ? Sure they can do that.
Cheapskate NAS Parade
I assembled a crowd of common Linux products, all costing less than £100. For testing, the same disk was connected to each. Not a disk, actually, but a Transcend Jetflash 8 Gb thumb drive. A spinning disk would have been faster, and a larger thumb drive more desirable, but this is just a comparative test, and for that the memory stick will do. The results:
|WD TV Live||100||9.0||5.0|
|Raspberry Pi (medium overclocking)||100||7.9||7.3|
|Raspberry Pi (not overclocked)||100||7.1||6.4|
|BT Home Hub 3||1000||5.9||3.2|
|BT Home Hub 3||100||4.6||2.9|
The test involved copying a 343 MB video file to and from each device in turn, from a gigabit connected laptop on the local network. Afterwards I attached the thumb drive straight to the laptop and measured the local copy time (recorded as “Reference” above).
The Sheevaplug and Linkstation are fitted with gigabit interfaces, allowing end-to-end gigabit. The BT Home Hub 3 has fast ethernet and gigabit interfaces, so I tried both.
The Sheevaplug is a clear winner. It easily saturates a 100 bas T connection. Routed over gigabit, speeds of 19.3 and 9.0 MB/s were achieved. Some way behind that is the next fastest contender, the WD TV Live, getting some pretty good throughput from its 100 base T interface. Disappointingly, the Linkstation, a dedicated NAS unit, albeit rather out-of-date now, is barely faster than a non-overlocked Raspberry Pi. The Pi is a pretty solid performer for reading and writing. Bringing up the rear is the BT Home Hub 3, a modem/router common on the UK. Even the gigabit connection was not enough to stop it coming in last.
A midrange domestic NAS unit would provide read and write speeds of about 50 MB/s or greater. Unsurprisingly, none of our devices gets anywhere near that. But all of them, even the Home Hub, are quick enough for streaming video and casual file sharing.
Those model names in full:
- Buffalo Linkstation Live HS DH500-GL, now obsolescent.
- WD TV Live model C3H (diskless)
- Sheevaplugrunning Debian 6.0 Squeeze.
- Raspberry PI model B (512 Mb) running Debian Wheezy
- BT Home Hub 3.0 type BThumb drive: Transcend Jetflash 600 8 Gb, formatted as vfat/Fat16.
All network connections routed directly through an standalone gigabit switch, including the connection to the BT Home Hub.
USB 2.0 throughout.