Since D-Link is silent, here is how I've done it with Opera user javascript.
Here is the tutorial on how to enable and use it: http://www.opera.com/support/tutorials/userjs/
After you enable the javascript, create a file in the user javascript folder you've created and enabled.
Call it for example dlink.js
Copy-paste the code below into the file replacing 192.168.1.1 with your D-link's IP.
Then use opera to log into D-link interface and proceed to format the drives using Raid 1 (that's what I needed). In the size text box enter 1500. If all goes well it wouldn't object against this number but will start formatting drives. That will take a while. Don't be alarmed when it gets stuck at some percent, the progress indicator sucks
The code below (if it will let me post). If not - email me at dlinkdns321 [at] gmail [dot] com
// ==UserScript==
// @include http://192.168.1.1/*
// ==/UserScript==
if(location.hostname.indexOf("192.168.1.1")>=0) {
window.opera.defineMagicFunction('reload',
function(oRealFunc, oThis) {
var limit_size=chg_HDUnit('0','1');
var sum=0;
limit_size = 1500;
if(document.form1.f_disk_mode.value=="raid0")
{
sum=parseInt(parseInt(limit_size)*2);
document.form1.AdvHDSize.value=sum;
}
else
{
document.form1.AdvHDSize.value=limit_size;
}
}
);
}