I decided to buy a NAS and remove the disks from my home server.
I didn’t want to spend too much money, since this was one of those non-essential projects. But equally, I didn’t want to spend too little and get something that would break and destroy all my data with it. Eventually I decided upon a Promise SmartStor NS4300N.
Features
It had all the features I wanted, including:
- SMB/CIFS for Windows clients
- NFS for Linux clients
- RAID5
- Gigabit Ethernet with Jumbo Frames
First impressions
So how did it shape up?
The build quality was relatively poor. It’s made from thin plastic and feels flimsy. The disk caddies are incredibly flimsy and flexible, and I felt nervous even handling them; but this didn’t matter because I planned to assemble it and leave it alone.
It wasn’t exactly quiet either. There is an 80mm fan for the disks and a 40mm fan for the internal PSU. The 80mm fan only spins when the disks are hot but it is very noisy when it does so. The 40mm fan is constant but not so loud. And of course there’s the sound of four hard disks, which varies depending on make and model. Overall, it’s probably quieter than a standard computer, but you wouldn’t want to sleep with it in your bedroom.
It’s not a problem for me because I’m putting it in the loft.
Setting it up
The initial setup wasn’t as straightforward as I thought it could (should?) have been, especially for beginners. But it wasn’t really much trouble to set up a RAID5 array with 4 x 500GB disks and format it, for a total of 1.4TB.
More confusing, perhaps, was the selection of different protocols and the layout for setting up users, shares and permissions.
I wanted to set up two shares, public and private and set public to be world-readable (for my media centre) and private to be accessible only by me. If you create these accounts on the NAS, it’s simple enough to tick the boxes and set the desired permissions on Windows (SMB/CIFS) shares.
But NFS was a different kettle of fish. No user-level permissions are available on the NAS for NFS, and the only control you get is a list of allowed IP addresses. By default the NAS says it allows *.*.*.* but I found that this didn’t let anyone in. Adding real IP addresses to the list worked.
However, I found that when you have data shared both as NFS and SMB/CIFS, the permissions go out of the window and are not respected at all. An unauthenticated guest user was able to read and delete files from my private share.
Performance
Performance was far worse than I had expected.
With the NAS mounted on my PC via NFS, it would only manage 4.8MB/s sustained write rate, and 13.5MB/s sustained read rate. That’s significantly worse than the sustained 30MB/s I used to get with the same disks in the server, as a Linux software RAID array. On top of that, writing at this speed tied up my computer’s quad-core CPU 100% with IOWait.
With the NAS mounted on the same PC via SMB, it was able to write sustained at 9.2MB/s.
This is really quite poor, given that the same set of disks when connected directly into the server with SATA could write at some 35MB/s.
It depends on your usage though – if you simply want to play music and videos from the NAS then 10MB/s is fine, even for high definition. However I use mine for large backups and I don’t want to wait almost ten times longer for the backups to complete.
Summary
- If you already have a NAS or storage server that you are happy with, don’t buy this.
- If you want to use NFS, don’t buy this.
- If you care about high performance, don’t buy this.
- If you want a reasonably-priced solution for backups or sharing media between computers, buy this. I reckon it would be fine to shove in a cupboard and simply drag your movies onto from your computer, so you could watch them on your media centre.
However, it didn’t cut the mustard with me, so I sent it back. I’ve now returned to my original system with the four disks hosted in the server. It’s fast and the permissions work fine – the downside is that I have to keep a large, noisy ATX tower case and can’t switch to an Intel Atom solution 😦
Jonathan Gazeley 