3. 如何增加或者删除swap分区
1、查看swap空间和使用情况
[root@localhost-zabbix ~]# swapon -s
Filename Type Size Used Priority
/dev/dm-1 partition 2097144 0 -1
[root@localhost-zabbix ~]# free -m
total used free shared buffers cached
Mem: 1877 565 1311 0 132 188
-/+ buffers/cache: 244 1632
Swap: 2047 0 2047
2、关闭swap
[root@localhost-zabbix ~]# swapoff /dev/dm-1 [root@localhost-zabbix ~]# swapon -s Filename Type Size Used Priority
3、启用之前关闭分区
[root@localhost-zabbix ~]# swapon /dev/dm-1 [root@localhost-zabbix ~]# swapon -s Filename Type Size Used Priority /dev/dm-1 partition 2097144 0 -1
4、缩小Swap分区
如果是增大Swap分区大小，那么就需要扩展正在使用的swap分区的逻辑卷,此处使用lvreduce命令收缩逻辑卷
[root@getlnx14uat ~]# lvreduce -L 8G /dev/mapper/VolGroup00-LogVol01 WARNING: Reducing active logical volume to 8.00 GB THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce LogVol01? [y/n]: y Reducing logical volume LogVol01 to 8.00 GB Logical volume LogVol01 successfully resized [root@getlnx14uat ~]# mkswap /dev/mapper/VolGroup00-LogVol01 #格式化 Setting up swapspace version 1, size = 8589930 kB [root@getlnx14uat ~]# swapon -s Filename Type Size Used Priority [root@getlnx14uat ~]# swapon /dev/mapper/VolGroup00-LogVol01 [root@getlnx14uat ~]# swapon -s Filename Type Size Used Priority /dev/mapper/VolGroup00-LogVol01 partition 8388600 0 -1
5、增大swap空间
如果磁盘还有剩余未分配空间可以新分区swap或者增大之前的swap
如果没有磁盘未分配，可以新建分区文件，来增大swap
[root@localhost-zabbix ~]# dd if=/dev/zero of=/home/swap bs=1024 count=1024000
记录了1024000+0 的读入
记录了1024000+0 的写出
1048576000字节(1.0 GB)已复制，2.69212 秒，389 MB/秒
[root@localhost-zabbix ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_localhostzabbix-lv_root 18G 4.7G 12G 29% /
tmpfs 939M 0 939M 0% /dev/shm
/dev/sda1 485M 33M 427M 8% /boot
[root@localhost-zabbix ~]# mkswap /home/swap
mkswap: /home/swap: warning: don't erase bootbits sectors
on whole disk. Use -f to force.
Setting up swapspace version 1, size = 1023996 KiB
no label, UUID=74c16b0d-7d88-4384-b41e-b12cc93d4bbf
[root@localhost-zabbix ~]# cd /home/
[root@localhost-zabbix home]# ls
swap
[root@localhost-zabbix home]# mkswap swap
mkswap: swap: warning: don't erase bootbits sectors
on whole disk. Use -f to force.
Setting up swapspace version 1, size = 1023996 KiB
no label, UUID=7677912c-b337-4e83-9003-b736dec93d31
[root@localhost-zabbix home]# free -m
total used free shared buffers cached
Mem: 1877 1611 265 0 135 1192
-/+ buffers/cache: 283 1593
Swap: 2047 0 2047
[root@localhost-zabbix home]# swapon swap
[root@localhost-zabbix home]# free -m
total used free shared buffers cached
Mem: 1877 1612 265 0 135 1192
-/+ buffers/cache: 284 1592
Swap: 3047 0 3047
[root@localhost-zabbix home]# swapon -s
Filename Type Size Used Priority
/dev/dm-1 partition 2097144 0 -1
/home/swap file 1023992 0 -2
