This was reported as an issue before when dual-booting Ubuntu with another distro. Basically the Swap UUID Doesn’t get updated in /etc/fstab when another distro is installed on another partition.
I installed Fedora for a test run on a spare partition, with Grub being installed to MBR.
Later after an Ubuntu update, which included a new kernel and also a newer Grub, Ubuntu took back control of Grub.
I booted into Ubuntu, only to find that everything was a bit sluggish, and having experienced this before, I checked my Swap partition in readiness to solve this problem which I had a feeling was repeating itself.
With the result:
Swap: 0 0 0
Fix with “blkid” to find the real UUID of the Swap Partition:
/dev/sda1: LABEL="ACER" UUID="320D-180E" TYPE="vfat"
/dev/sda2: LABEL="Fedora-12-i686-L" UUID="3b915b51-c7ce-4077-975d-df2a177b94cb" TYPE="ext4"
/dev/sda3: UUID="78a42ee0-4d8a-474c-9cd6-b3f3a6dd6449" TYPE="ext4"
/dev/sda4: UUID="4bfbb29b-78da-4172-ae54-b1bb934de7f5" TYPE="swap"
Then use Nano to Fstab and change the old Swap UUID to the new UUID:
sudo nano /etc/fstab
Now just turn Swap on and check used memory again:
sudo swapon -a
with the result:
Swap: 1153 0 1153
So there you have it, if you install another Linux distro on a spare partition to dual-boot and use the same Swap partition, you may find that when you boot into Ubuntu that it is a little sluggish than usual.
This is a known problem for dual and triple booters, but easily remedied, as you see above.