How to determine what partition is still not formatted?

[Joe Smith]

Tim wrote:
> ...
> Just typing in mount will show you what's mounted.  You can compare that
> against fdisk -l to find out more about what's missing.

As long as there are no partitions that have been formatted but not mounted.

AFAIK the only way to see if a partition is formatted is to try and 
mount it. Mount can try to determine how the partition is formatted, so 
if it gives up you can be pretty sure that partition is not formatted, 
at least for any filesystems the kernel has support for.

I actually keep a disk/partition inventory, by hand, in a spreadsheet, 
because I've never found a good admin tool that can print a nice summary 
of the info I need to know (e.g., the OP's question) when installation 
time rolls around. It doesn't change often so it's not a huge chore, but 
if anyone has a better solution, I'd love to hear it.

<Joe