#需求
因系统内存资源紧张急需添加10G swap 交换空间
#创建存放swap文件的目录
[root@localhost ~]# mkdir /swap
#创建一个10G空文件
[root@localhost ~]# dd if=/dev/zero of=/swap/swap bs=1024M count=10 10+0 records in 10+0 records out 10737418240 bytes (11 GB) copied, 20.745 s, 518 MB/s
#格式化为交换空间
[root@localhost ~]# mkswap /swap/swap mkswap: /swap/swap: warning: don't erase bootbits sectors on whole disk. Use -f to force. Setting up swapspace version 1, size = 10485756 KiB no label, UUID=844fb94b-c5e5-4d55-a091-c310b9e5e289
#查看系统内存
[root@VM_37_0_centos ryzc]# free -m total used free shared buffers cached Mem: 24028 22842 1185 0 149 3530 -/+ buffers/cache: 19162 4866 Swap: 2047 1127 920
#添加交换空间
[root@localhost ~]# swapon /swap/swap
#再次查看系统内存
[root@localhost ~]# free -m total used free shared buffers cached Mem: 24028 22888 1139 0 150 3563 -/+ buffers/cache: 19174 4853 Swap: 12287 1125 11162
#开机自启动设置,法1:放到开机启动
[root@localhost ~]# tail -1 /etc/rc.local swapon /swap/swap
#法2:放到/etc/fatab
[root@localhost opt]# tail -1 /etc/fstab /swap/swap swap swap defaults 0 0
#删除swap
[root@localhost ~]# swapoff /swap/swap [root@localhost ~]# rm -rf /swap/swap