新建swap分区的规划、挂载和自动挂载示例

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mb5ff9827b65e5b 2018-06-28 13:45:00

文章标签 linux sed 磁盘分区自动挂载 linux系统管理 文章分类 代码人生

注：来自Linux系统管理_磁盘分区和格式化的扩展

思路：

第一步：首先查看当前swap分区的大小：free -m

第二步：新建磁盘分区指定状态为82，即为swap分区格式：fdisk命令

第三步：重读磁盘分区：partprobe命令

第四步：格式化swap分区：mkswap命令

第五步：手动挂载和卸载swap分区：swapon/off

第六步：设置开机自动挂载swap分区：swapon -a

具体操作：

第一步：首先查看当前swap分区的大小：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：新建磁盘分区指定状态为82，即为swap分区格式：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: 设备或资源忙.

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：重读磁盘分区：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分区：mkswap命令

[root@localhost ~]# mkswap /dev/sda6

Setting up swapspace version 1, size = 1011671 kB

第五步：手动挂载和卸载swap分区：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        //查看都有哪些交换分区挂载

Filename                                Type            Size    Used    Priority

/dev/sda5                               partition       2096440 0       -1

/dev/sda6                               partition       987956  0       -3

[root@localhost ~]# swapoff /dev/sda6        //卸载swap分区

[root@localhost ~]# swapon -s

Filename                                Type            Size    Used    Priority

/dev/sda5                               partition       2096440 0       -1

第六步：设置开机自动挂载swap分区

[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        //编辑/etc/fstab文件，增加下面内容

[root@localhost ~]# cat /etc/fstab | grep sda6    //将下面的信息添加到/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来重读/etc/fstab文件，使新swap分区挂载

[root@localhost ~]# swapon -s       //再次用swapon -s查看的时候，新的swap分区sda6成功挂载

Filename                                Type            Size    Used    Priority

/dev/sda5                               partition       2096440 0       -1

/dev/sda6                               partition       1959888 0       -5

[root@localhost ~]#