注：來自Linux系統管理_磁盤分區和格式化的擴展
Linux系統管理_磁盤分區和格式化：http://murongqingqqq.blog.51cto.com/2902694/1361918
思路：
第一步：首先查看當前swap分區的大小：free -m
第二步：新建磁盤分區指定狀態為82，即為swap分區格式：fdisk命令
第三步：重讀磁盤分區：partprobe命令
第四步：格式化swap分區：mkswap命令
第五步：手動掛載和卸載swap分區：swapon/off
第六步：設置開機自動掛載swap分區：swapon -a
具體操作：
第一步：首先查看當前swap分區的大小：free -m
[root@localhost ~]# free -m total used free shared buffers cached Mem: 495 285 209 0 18 167 -/+ buffers/cache: 99 395 Swap: 2047 0 2047 [root@localhost ~]# fdisk -l /dev/sda Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 25 200781 83 Linux /dev/sda2 26 2575 20482875 83 Linux /dev/sda3 2576 3850 10241437+ 83 Linux /dev/sda4 3851 7832 31985415 5 Extended /dev/sda5 3851 4111 2096451 82 Linux swap / Solaris
第二步：新建磁盤分區指定狀態為82，即為swap分區格式：fdisk命令
[root@localhost ~]# fdisk /dev/sda The number of cylinders for this disk is set to 7832. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): n First cylinder (4112-7832, default 4112): Using default value 4112 Last cylinder or +size or +sizeM or +sizeK (4112-7832, default 7832): +1G Command (m for help): p Disk /dev/sda: 64.4 GB, 64424509440 bytes 255 heads, 63 sectors/track, 7832 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 25 200781 83 Linux /dev/sda2 26 2575 20482875 83 Linux /dev/sda3 2576 3850 10241437+ 83 Linux /dev/sda4 3851 7832 31985415 5 Extended /dev/sda5 3851 4111 2096451 82 Linux swap / Solaris /dev/sda6 4112 4234 987966 83 Linux Command (m for help): t Partition number (1-6): 6 Hex code (type L to list codes): 82 Changed system type of partition 6 to 82 (Linux swap / Solaris) Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: 設備或資源忙. The kernel still uses the old table. The new table will be used at the next reboot. Syncing disks. [root@localhost ~]# ls /dev/sd* /dev/sda /dev/sda1 /dev/sda2 /dev/sda3 /dev/sda4 /dev/sda5
第三步：重讀磁盤分區：partprobe命令
[root@localhost ~]# partprobe [root@localhost ~]# ls /dev/sd* /dev/sda /dev/sda1 /dev/sda2 /dev/sda3 /dev/sda4 /dev/sda5 /dev/sda6
第四步：格式化swap分區：mkswap命令
[root@localhost ~]# mkswap /dev/sda6 Setting up swapspace version 1, size = 1011671 kB
第五步：手動掛載和卸載swap分區：swapon/off
[root@localhost ~]# free -m total used free shared buffers cached Mem: 495 287 208 0 18 168 -/+ buffers/cache: 99 395 Swap: 2047 0 2047 [root@localhost ~]# swapon /dev/sda6 [root@localhost ~]# free -m total used free shared buffers cached Mem: 495 287 207 0 18 168 -/+ buffers/cache: 100 395 Swap: 3012 0 3012 [root@localhost ~]# swapon -s //查看都有哪些交換分區掛載 Filename Type Size Used Priority /dev/sda5 partition 2096440 0 -1 /dev/sda6 partition 987956 0 -3 [root@localhost ~]# swapoff /dev/sda6 //卸載swap分區 [root@localhost ~]# swapon -s Filename Type Size Used Priority /dev/sda5 partition 2096440 0 -1
第六步：設置開機自動掛載swap分區
[root@localhost ~]# cat /etc/fstab LABEL=/ / ext3 defaults 1 1 LABEL=/data /data ext3 defaults 1 2 LABEL=/boot /boot ext3 defaults 1 2 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 LABEL=SWAP-sda5 swap swap defaults 0 0 [root@localhost ~]# vim /etc/fstab //編輯/etc/fstab文件，增加下面內容 [root@localhost ~]# cat /etc/fstab | grep sda6 //將下面的信息添加到/etc/fstab文件 /dev/sda6 swap swap defaults 0 0 [root@localhost ~]# swapon -s Filename Type Size Used Priority /dev/sda5 partition 2096440 0 -1 [root@localhost ~]# swapon -a //用swapon -a來重讀/etc/fstab文件，使新swap分區掛載 [root@localhost ~]# swapon -s //再次用swapon -s查看的時候，新的swap分區sda6成功掛載 Filename Type Size Used Priority /dev/sda5 partition 2096440 0 -1 /dev/sda6 partition 1959888 0 -5 [root@localhost ~]#
擴展：swap分區開機自動掛載的第二種方式：
第一步：修改/etc/rc.d/rc.local文件
第二步：將swapon /dev/sda6寫入這個腳本當中，那么開機就可以自動掛載交換分區/dev/sda6了！！！
注：用swapon -a和reboot命令來實現重讀/etc/fstab文件，實現開機自動掛載。
普通分區重讀/etc/fstab文件的時候用mount -a，swap分區重讀/etc/fstab文件的時候，
使用swapon -a