Linux環境下Swap配置方法

Linux環境下Swap配置方法

場景:
今天下午安裝一個CentOS6.5操做系統，忘記配置swap分區。看看如何安裝系統以後，增長和刪除swap分區。
方法以下：
1.內存佔用狀況
[root@joshua ~]# free -m
total used free shared buffers cached
Mem: 2006 1886 119 31 33 574
-/+ buffers/cache: 1278 727
Swap: 0 0 0
2.經過dd命令增長swap，增長一個2g的swap空間
[root@joshua ~]# dd if=/dev/zero of=/var/swap bs=1024 count=2048000
2048000+0 records in
2048000+0 records out
2097152000 bytes (2.1 GB) copied, 36.4509 s, 57.5 MB/s

3.建立swap文件
[root@joshua ~]# mkswap /var/swap
mkswap: /var/swap: warning: don't erase bootbits sectors
on whole disk. Use -f to force.
Setting up swapspace version 1, size = 2047996 KiB
no label, UUID=eba0b718-b5d0-488f-a368-0af288def8b6

[root@joshua ~]# mkswap -f /var/swap
Setting up swapspace version 1, size = 2047996 KiB
no label, UUID=5039b019-2db5-41b2-a289-3caf4fdd98bf
[root@joshua ~]#

4.加載該文件：
[root@joshua ~]# swapon /var/swap
5.看看swap是否生效
[root@mysql01 var]# free
6.查看swap當前狀態：
[root@joshua ~]# cat /proc/swaps
Filename Type Size Used Priority
/var/swap file 2047996 0 -1

7.添加至/etc/fstab , vim /etc/fstab

#
# /etc/fstab
# Created by anaconda on Thu Aug 24 12:21:20 2017
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=1ae5f12f-79c1-47d4-bed7-941ab9385396 / ext4 defaults 1 1
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/var/swap swap swap defaults 0 0

8.若是再也不須要swap，能夠清理該分區：
[root@joshua ~]# swapoff /var/swap