What is (isn't) Network Attached Storage?

Is Network Attached Storage a box you connect to your switch through Ethernet, that appears on the network as a drive, and can be mapped in Windows as a logical drive letter and accessed by multiple computers, and configured through a web browser, without installing special software on the computers?

That’s what I want. I hoped I could buy something labeled “NAS” and get it.

But the ones I am finding for sale online all have software disks with them and list which versions of OS they are compatible with. Why?

Maybe the software is for backup, multimedia play, or other stuff I don’t want. Maybe I can ignore it. In a couple cases, user reviews seem to say this.

But I don’t want a repeat of the experience I had a few years ago when I bought something I thought was that, and it turned out to only be accessible through special software you have to install on the user computer. One user could activate the device by using the software, but had to execute a special function to release the hardware so other users could access it. Worse, it didn’t appear exactly like a drive - in particular, it rearranged files when it stored them, and organized them strictly by extension (or "type).

How can I make sure I’m getting something that just looks like a remote logical drive?

The phrase NAS means nothing in terms of the way the storage is accessed via the network. However, in contrast to older devices, modern devices should support CIFS (ie Windows style network shares), as well as possibly some other common network file types (NFS maybe). The disk supplied may include software for remote configuration, some tools to help you find the device, and maybe some backup software. The supported systems list is to give non-technical users some comfort that the product will work with their system.

Generally, the biggest issue is setting up. If the NAS server is configured by DHCP, you don’t know what it’s address will be. Network browsing probably won’t work, either (due to workgroup name mismatch. So the software disk configures everything so that such things do work.

Look for DHCP and CIFS (or maybe samba, the free UNIX CIFS server software).

Si

I’m sure you know this, but for explicit clarity: assuming one has administrative rights to the router, this shouldn’t be a problem after initial setup – most routers (that I’m familiar with) allow one to assign a specific address to a particular piece of hardware (i.e., MAC).

In other words, the NAS will use DHCP, but (magically!) gets the same address every time from the router.

I recommend looking into ReadyNAS made by Netgear. I have one it does exactly what you want. It does require some knowledge of networking protocols to set up and the documentation is a sparser than I would like. However, there is a fairly large user community which offers support and tips.

Yeah, but it is finding the device initially that can be a problem. The NAS setup software usually interrogates the local arp table to find any MAC addresses that match the manufacturer (MAC addresses are assigned by manufacturer), and then gives you the option to configure those devices. Manufacturers expect that users do not understand how to set up a DHCP reservation, so attempt to make the configuration as simple and as automated as possible without going to that level.

Si

Often software disks with networking products are easy setup utilities or something similiar, but are not actually required to be used.

There are dozens of NAS boxes on the market that will do what you want:

The already mentioned Netgear Readynas
Seagate Blackarmour
D-Link DNS 323,313,343
Lacie Network Drive (or something)
Buffalo Terastations, Linkstations

Western Digital have a couple of well but I have heard that their software is a pain to use (Mionet).

Mmmm. I forgot about DHCP. I don’t like it, partly because I have some network devices that require static IP. And I had a problem a few years back with something that insisted on doing DHCP, and every so often they would assign the same address one of the static things was using, and the system would misbehave (I’ve heard conflicting stories about how mixed DHCP and static systems are supposed to behave, including schemes for having DHCP servers exclude part of the range that don’t work right).

These days I have an ISP-supplied cable modem that insists on being a DHCP host, so I put a router (I mean literally a real router, not a hub or switch) with its WAN side in DHCP client mode facing the modem and its LAN side in static mode facing my switch, and have it doing NAT.

Can I set these NAS devices for static IP? Or can I maybe put them on the WAN side of the router so they can run as DHCP clients?

Sure you can set them for static. Heck, a lot of them come with samba and advertise themselves on a windows network. So if you name it ‘mynas’ then windows devices will be able to resolve ‘mynas’ to its proper IP even after its changed several times.

Static is safe, especially if you have a mixed network.

>These days I have an ISP-supplied cable modem that insists on being a DHCP host, so I put a router (I mean literally a real router, not a hub or switch) with its WAN side in DHCP client mode facing the modem and its LAN side in static mode facing my switch, and have it doing NAT.

Err, you probably dont want to do double NAT. Id consider putting the devices on the high end of the dhcp scope (if you cannot change it in the router) like in the 200’s in a 255.255.255.0 network. So make your NAS 192.168.1.200. You’ll never have that many dhcp leases to conflict with it if you scope starts in the single digits. Now put that in your hosts file like so:

192.168.1.200 mynas

Use the name, not the IP.

But, the problem I had before - IIRC - was that the DHCP host would always choose a new address that was higher than all the others, until it reached the top of the space (255 or 254 or whatever it would be), and then wrapped around. Depending on how often people rebooted, every few weeks everything would die.

Are there rules governing how hosts must choose new addresses?

Or just build your own.

Your DHCP host will allow you to define a range of IP addresses that are available for allocation (the DHCP Pool). If you place (and document) all your static hosts outside that pool, there will never be a conflict.

As I stated above, the biggest problem is with inital setup - the NAS box almost certainly comes with DHCP enabled, and relies on the setup disk to find and configure the box (once you have that, you can allocate a static IP address). Without DHCP on the network, it will be awkward to configure (which will involve finding out what the default IP address for the NAS box is, changing a computer to have an IP address in the same range, and then configuring the NAS box to the new address, changing the computer IP address back again…

DHCP is much easier and faster, and you can use long leases and reservations to give “static” IP addresses as needed.

Si

In addition to basic functionality, you probably want to consider performance as well. There’s a wide range of performance even at similar price and capacity points. One of the best sites for information is SmallNetBuilder (no financial connection, though they did once run an article about a NAS system I designed and built).

>Are there rules governing how hosts must choose new addresses?

Yes, typically there is a lease life per IP address. This is associated with the mac address of the device on the network. I think its typical for a lot of devices to ship with a 7 day lease. I guess in your case the lease was very, very long which defeats the purpose of DHCP.

This exactly what I did at home.

I didn’t have the $$$ to go out and buy a NAS, but I did have a spare PC at home and a slew of hard drives, so I built my own NAS and it cost me practically nothing.

I used FreeNAS for the OS. It was relatively easy to set up and it has so many features.