One, add swap space:
1. Extend an existing swap space:
<1> prohibit the swap space in use first:
[Root@server4 ~]# Swapoff/dev/mapper/tools-swap
<2>, re-resize/dev/mapper/tools-swap:
[Root@server4 ~]# LVM lvresize/dev/tools/swap-l +300m
Extending logical volume Swap to 500.00 MB
Logical Volume swap successfully resized
<3> reformatting using Mkswap:
[Root@server4 ~]# Mkswap/dev/tools/swap
Setting up Swapspace version 1, size = 524283 KB
<4>, enable swap:
[Root@server4 ~]# Swapon-av
Swapon On/dev/mapper/tools-swap
<5> View Swap Size:
[root@server4 ~]# cat/proc/swaps
filename type size used Priority
/dev/sda3 partition 1044216 0 -2
/ dev/mapper/tools-swap partition 511992 0 -4
[Root@server4 ~]# Free-m
Total used free shared buffers Cached
mem:194 172 21 0 19 78
-/+ buffers/cache:75 119
swap:1519 0 1519
2. Add a new swap space (based on LVM):
[Root@server4 ~]# LVM lvcreate tools-n swap1-l 100M
Logical volume "Swap1" created
[Root@server4 ~]# Mkswap/dev/tools/swap1
Setting up Swapspace version 1, size = 104853 k
Change/etc/fstab file and join/dev/tools/swap1.
To enable the newly created swap space:
[Root@server4 ~]# Swapon-av
Swapon On/dev/mapper/tools-swap1
[Root@server4 ~]# Free-m
Total used free shared buffers Cached
mem:194 173 20 0 19 78
-/+ buffers/cache:75 118
swap:1619 0 1619
3. Create swap file:
[Root@server4/]# dd If=/dev/zero of=/swapfile bs=1k count=102400
102400+0 Records in
102400+0 Records out
104857600 bytes (MB) copied, 1.23157 seconds, 85.1 MB/s
[Root@server4/]# Mkswap/swapfile
Setting up Swapspace version 1, size = 104853 KB
[Root@server4/]# Swapon/swapfile
Add the following line to the/etc/fstab file:
/swapfile Swap Defaults 0 0
Second, delete swap space:
1. Reduce a swap space:
[root@server4/]# swapoff/dev/mapper/tools-swap
[root@server4/]# lvm lvreduce/dev/tools/swap-l -400M
; Warning:reducing Active Logical Volume to 100.00 MB
i DESTROY YOUR DATA (filesystem etc.)
Do your really want to reduce swap? [y/n]: y
reducing logical volume swap to 100.00 MB
Logical Volume swap successfully resized
[roo T@server4/]# mkswap/dev/tools/swap
Setting up swapspace version 1, size = 104853 KB
[root@server4/]# Swapon-va
Swapon On/dev/mapper/tools-swap
[Root@server4/]# LVs
LV VG Attr lsize Origin snap% move Log copy% Convert
Swap Tools-wi-ao 100.00M
Swap1 Tools-wi-ao 100.00M
2. Remove an LVM-based swap:
[Root@server4/]# Swapoff/dev/tools/swap1
[Root@server4/]# LVM Lvremove/dev/tools/swap1
Do your really want to remove active logical Volume "SWAP1"? [y/n]: Y
Logical volume "Swap1" successfully removed
Then remove it from the/etc/fstab file.
3. Delete a swap file:
[Root@server4/]# swapoff-v/swapfile
[Root@server4/]# Rm-rf/swapfile