We have already discussed about use of swap space and the amount of swap size. To increasing swap size have used dd command and swap partition.
Another option is can make a swap size of the Logcal volume (LVM). For this post  increase +2GB for swap space.

Current RAM memory and swap size satus,

# free -m
             total       used       free     shared    buffers     cached
Mem:          1777       1654        122          0          9        404
-/+ buffers/cache:       1240        537
Swap:         3672         155        3517

create a swap Logical volume:

-p Specified that print the partition,
-n Specified to create new partition
-t Type of partition (for LVM code type 8e)
-w Specified that write the changes (save)
# fdisk /dev/sda

The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.

Command (m for help):   n
All primary partitions are in use
Adding logical partition 15
First sector (491483136-579295231, default 491483136):
Using default value 491483136
Last sector, +sectors or +size{K,M,G} (491483136-579295231, default 579295231): +10G

Command (m for help):   p
Device Boot      Start            End               Blocks        Id  System
/dev/sda15      491483136   493531135     1024000   83  Linux

Command (m for help):   t
Partition number (1-15):   15
Hex code (type L to list codes):   8e
Changed system type of partition 15 to 8e (Linux LVM)

Command (m for help):  p
Device Boot      Start            End               Blocks        Id  System
/dev/sda15      491483136   493531135     1024000   8e  Linux

Command (m for help):   w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

It's necessary to reboot the system, once  LVM partitioned

Crate physical volume:

# pvcreate /dev/sda15

  Physical volume "/dev/sda15" successfully created

Check your physical volume  size:

# pvs

  /dev/sda15 swaps lvm2 a--    10.00g    9.02g

Create Volume Group:

# vgcreate swaps /dev/sda15

  Volume group "swaps" successfully created

Displaying volume group swaps details:

# vgdisplay swaps

  --- Volume group ---
  VG Name               swaps
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               10.00 GiB
  PE Size               4.00 MiB
  Total PE              2559
  Alloc PE / Size       0 / 0   
  Free  PE / Size       2559 / 10.00 GiB
  VG UUID               cBIjt0-lXNB-07gQ-7q7G-HMjV-4zyC-dO4a63

Create a new swap space:

# mkswap /dev/mapper/swaps-swap1

mkswap: /dev/mapper/swaps-swap1: warning: don't erase bootbits sectors
        on whole disk. Use -f to force.
Setting up swapspace version 1, size = 1023996 KiB
no label, UUID=e989f379-f428-4581-83f9-8bc42079c431

Tuning on swap space,

# swapon -v /dev/mapper/swaps-swap1

swapon on /dev/mapper/swaps-swap1
swapon: /dev/mapper/swaps-swap1: found swap signature: version 1, page-size 4, same byte order
swapon: /dev/mapper/swaps-swap1: pagesize=4096, swapsize=1048576000, devsize=1048576000

# swapon -s

Filename                                Type            Size    Used    Priority
/dev/sda1                               partition       5858300 159356  -1
/dev/mapper/swaps-swap1                 partition       1023996 0       -2

parmanently swapon for every reboot system Open a /etc/fstab file and add the line
UUID=e989f379-f428-4581-83f9-8bc42079c431 swap           swap   defaults      0       0

Swap space off:

You want to remove the line from the file "/etc/fstab" and execute swapoff command,
UUID=e989f379-f428-4581-83f9-8bc42079c431 swap           swap   defaults      0       0

# swapoff /dev/mapper/swaps-swap1