During the setup of additional swap space on an ext2 filessystem, you encounter an error as shown below: 
Which action must you perform to add additional swap space?
A.
Create a symbolic link /dev/swapfile that points to u01/swapfile.
B.
Reinitialize /u01/swapfile by issuing mkswap –L swapfile /u01/swapfile.
C.
Re-create the swapfile on an ext3 or ext4 filesystem.
D.
Change LABEL=swapfile to /u01/swapfile in the appropriate /etc/fstab entry.
E.
None, because adding filesystem based swap space is not supported.
Explanation:
D
[root@OraLinux6 /]# dd if=/dev/zero of=/u02/swapable bs=1M count=512
512+0 records in
512+0 records out
536870912 bytes (537 MB) copied, 0.971195 s, 553 MB/s
[root@OraLinux6 /]#
[root@OraLinux6 u02]# mkswap -f -L swapfile /u02/swapable
Setting up swapspace version 1, size = 524284 KiB
LABEL=swapfile, UUID=57a76404-c574-4846-82d5-0fc61dc9345a
[root@OraLinux6 u02]#
[root@OraLinux6 u02]# grep swap /etc/fstab
UUID=babb3572-7bcd-4ddf-954f-093404ad3537 swap swap defaults 0 0
LABEL=swapfile swap swap defaults 0 0
[root@OraLinux6 u02]#
[root@OraLinux6 u02]# swapon -a
swapon: cannot find the device for LABEL=swapfile
[root@OraLinux6 u02]#
[root@OraLinux6 u02]# vi /etc/fstab
/u02/swapable swap swap defaults 0 0
[root@OraLinux6 u02]#
[root@OraLinux6 u02]# swapon -a
[root@OraLinux6 u02]# swapon -s
Filename Type Size Used Priority
/dev/sda2 partition 1048572 0 -1
/u02/swapable file 524284 0 -2
[root@OraLinux6 u02]#
Good Luck!!!!
D