From: Yousuf Khan on
Jason Stacy wrote:
> Assume I have a second hard disc in my system.
> Can I put only one extended/logical partiton on it?
>
> or is at least one primary partition per hard disc necessary?

There should be no problem putting just an extended partition on a disk
these days. The only minor quibble you might have with it is that the
extended partition takes up one entire sector of the disk, so there
would be one less sector for your data. But these days you'll never
notice that little bit of space lost.

Yousuf Khan