1.添加swap文件
1)生成swap文件
# dd if=/dev/zero of=/var/swapfile bs=1024 count=2048000
2)格式化swap文件
# mkswap /var/swapfile
3)授权swap文件
# chmod -R 0600 /var/swapfile
4)激活并挂swap文件
# swapon /var/swapfile
5)配置swap文件开机自动挂载
# vi /etc/fstab
/var/swapfile swap swap defaults 0 0
# mount -a
2.扩展现有swap lv
1)查卷组,验证卷组内是否有空闲空间用于扩展swap lv
# vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 28.99 GiB
PE Size 4.00 MiB
Total PE 7422
Alloc PE / Size 7398 / <28.90 GiB
Free PE / Size 24 / 96.00 MiB
VG UUID 3OjHXT-Xbzk-ti6Q-Vgqj-uTyW-xQBx-me66kb
2)查看swap lv
# lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID c4WXnf-Ihp8-VRRI-t8Q4-m7JF-s6yn-PgLocQ
LV Write Access read/write
LV Creation host, time localhost, 2018-10-19 11:28:14 +0800
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/centos/root
LV Name root
VG Name centos
LV UUID vrfVBH-PI1m-G6W3-78d3-f3dz-9ITQ-ZMQcmT
LV Write Access read/write
LV Creation host, time localhost, 2018-10-19 11:28:14 +0800
LV Status available
# open 1
LV Size <26.90 GiB
Current LE 6886
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
3)扩展swap lv
# lvextend -L 2050MB /dev/centos/swap
4)关闭和转换swap lv
# swapoff /dev/centos/swap
# mkswap /dev/centos/swap
5)激活swap lv
# swapon /dev/centos/swap
# free -h