Using the same swap space for different linux installations

I  want to upgrade my server to 11.04 now I have tried it on my laptop. However as this can take some time until I have all of the services configured I decided to make some space free and install the 11.04 server on a separate partition.

I notice that the installation automatically reserves some swap space for the new Ubuntu installation, even though there is an existing linux swap partition. This seems wasteful to me so I looked up the UUID for the existing swap space using

suso blkid

or by mounting the other linux on /mnt with for example

sudo mount /dev/sda1/ /mnt

 and looking under /mnt/etc/fstab for the UUID for the swap

The replace the swap UUID in /etc/fstab with the existing one.

You  can then use GParted to utilize the new swap space for something else.