UNIX for Dummies Questions & Answers

Hi,

I am having some problems understanding the info from the following output:

Disk /dev/sda: 17849 cylinders, 255 heads, 63 sectors/track
Units = cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0

Device Boot Start End #cyls #blocks Id System
/dev/sda1 * 0+ 499 500- 4016218+ 83 Linux
/dev/sda2 500 999 500 4016250 82 Linux swap / Solaris
/dev/sda3 1000 17848 16849 135339592+ 83 Linux
/dev/sda4 0 - 0 0 0 Empty


I wan to know how large each partition is. I selected the size for /dev/sda2 in fdisk to be 1000M but if I am understanding the info correctly I only have 0.5megs for /dev/sda2. Can someone tell me how to effectively create partition sizes in fdisk? it seems when I try and specify the size using the actual size it does not work well.

One other question:
/dev/shm 517172 0 517172 0% /dev/shm

Is /dev/shm the swap partition /dev/sda2?

Thanks!