Setting Up A Low Cost NAS Using Tomato

In this post I’ll describe the steps needed to setup a low cost NAS using the Tomato firmware on the Asus 520gu.  This should work with Asus 500 as well.

If you have no idea what a NAS is, think of it as a shared stor­age device within your home net­work that you can access via an ip address to store and retrieve doc­u­ments, wire­lessly. If you and your wife/girlfriend/partner have two sep­a­rate com­put­ers, you could store, say vaca­tion pho­tos in this shared stor­age. This device would appear as a folder/drive on both a Mac and a PC. You can sim­ply drag and drop files to it.

What you need:

• Asus WL-520gu or Asus WL-500g
• An exter­nal usb stor­age device either pow­ered or flash based

A note about our home­brew NAS…
I’m going to tell what most don’t about set­ting up a USB Wifi NAS. It is pretty cool to put to good use your spare usb drive or exter­nal hard­disk. But don’t expect blaz­ing speeds.

Stor­ing files, doc­u­ments, music, pho­tos are fine. But if you are think­ing of doing a hard drive backup or store full length videos, the speeds may not be acceptable.

But don’t let that dis­cour­age you! It is still pretty cool! We use it as a back up stor­age device for our pho­tos and serves that pur­pose pretty well!

For­mat­ting the USB drive
Tomato sup­ports these filesys­tems:
FAT32 (Windows/Mac/Linux)
FAT16 (Windows/Mac/Linux)
EXT2 (Linux)
EXT3 (Linux)

When you buy a hard drive, it is most likely for­mat­ted to FAT32 since most oper­at­ing sys­tems sup­port it with­out hav­ing to install addi­tional drivers.

So why pick another filesys­tem?
FAT32 is by Microsoft! If that doesn’t con­vince you, you have a file size lim­i­ta­tion of 4GB, plus FAT32 pro­vides no secu­rity and in gen­eral quite inefficient.

FAT16. Don’t even con­sider it! This was the stan­dard used by old MS DOS OS.

EXT2 is mostly used by Linux Oper­at­ing Sys­tems. Nei­ther Win­dows nor Mac can read EXT2 dri­ves natively

EXT3 is EXT2 with jour­nalling enabled. With­out the tech­nob­a­b­ble, that means EXT3 helps pre­vents file cor­rup­tion in case of an non grace­ful sys­tem shut­down (if you sim­ply pull the USB drive out with­out unmount­ing it first)

EXT3 is most pre­ferred. But the dis­ad­van­tage is once for­mat­ted to this for­mat, you can’t plug in your USB drive to your PC or Mac and try to read or write files. You need a Linux sys­tem to do that. (There are ways to get PCs and Macs rec­og­nize EXT2/EXT3 dri­ves, but that involves addi­tional work).

The biggest advan­tage of FAT32 is most dri­ves come pre­for­mat­ted to this for­mat. You can plug in the USB drive to your Mac or PC and you will be able to see this drive as another mount point.

What I’ve done is par­ti­tioned my old Sea­gate 160GB hard drive to both FAT32 and EXT3. They now appear as two mount points on both Win­dows and Mac.

If all this is too tech­ni­cal, just plug in darn drive into the ASUS router! Chances are that it’ll just work!

Get­ting Started
Set up Tomato on the Asus router

In the admin screen goto USB and NAS

Your con­fig should look like the screen­shot above with the excep­tion of Attached Devices.  Don’t attach the USB device yet.  Save the con­fig­u­ra­tion above and restart the router.  Now, come back to this screen and you should see your stor­age device listed.

If the device shows up as not mounted, make sure the hard drive is for­mat­ted to either FAT or EXT and not HFS+ (Mac) or NTFS(XP).  Both are not sup­ported and the hard drive will have to be refor­mat­ted. Restart the router with the USB drive plugged in.  Check this screen, the device should show up as mounted.

If you’ve got­ten this far, you are almost there!  Get­ting the device to mount is usu­ally the biggest hur­dle.  Now using tel­net login to 192.168.1.1:

Trying 192.168.1.1...
Connected to davinci.
Escape character is '^]'.
davinci login: root
Password:

Tomato v1.23.8615 ND USB

BusyBox v1.12.3 (2009-01-28 23:18:53 EST) built-in shell (ash)
Enter 'help' for a list of built-in commands.

root@davinci:/tmp/home/root# cd /mnt
root@davinci:/tmp/mnt# ls
disc0_1 disc0_2
root@davinci:/tmp/mnt#


disc0_1 and disc0_2 are the par­ti­tions in my USB drive. If you have only one par­ti­tion, you’ll see only one disc. Note down this info.

Go to File Shar­ing under USB and NAS. Enter the info as in this screen­shot below:

For each direc­tory under /mnt, give a share name and descrip­tion and save. Set the code page and work­group name (Win­dows default is work­group). Set the access level to Read/Write. Save.

Now on a Mac:
Open Finder
Goto Go..Connect to Server

You will now be dis­played the mount points and your share will appear under ‘Shared’ in Finder!

On a PC:
Your shares should appear auto­mat­i­cally in Net­work Neigh­bor­hood with the share name you specified

Now you drag and drop files to your NAS device over a wifi net­work. Pretty cool huh?!