分区扩展Swap空间

分区扩展Swap空间

1)从磁盘sda上划分一个2G的分区sda8
2)将/dev/sda8格式化为Swap文件系统
3)启用/dev/sda8分区，查看Swap空间大小
4)停用/dev/sda8分区，查看Swap空间大小

首先要明白Swap分区空间是来源于硬盘，而要想扩充Swap空间的大小，思路很简单就是把硬盘的分区格式成Swap文件系统，再扩充到Swap空间中区。
对于Swap分区有它独立的格式化命令和扩充命令，这里要和普通分区的格式化命令和挂载命令区分开。此外它还有独立查看Swap空间组成的命令。

步骤一：从磁盘sda上划分一个2G的分区sda8

[root@localhost ~]# parted /dev/sda p  //查看分区表信息，主要是查看最后一个分区结束点
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sda: 322GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End    Size    Type      File system     标志
 1      1049kB  211MB  210MB   primary   ext4            启动
 2      211MB   105GB  105GB   primary   ext4
 3      105GB   210GB  105GB   primary   ext4
 4      210GB   322GB  112GB   extended
 5      210GB   219GB  8590MB  logical   linux-swap(v1)
 6      219GB   220GB  1481MB  logical   ext4
 7      220GB   221GB  999MB   logical

[root@localhost ~]# parted /dev/sda mkpart logical ext4 221G 223G
警告: WARNING: the kernel failed to re-read the partition table on /dev/sda (设备或资源忙).  As a
result, it may not reflect all of your changes until after reboot.
[root@localhost ~]# parted /dev/sda p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sda: 322GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End    Size    Type      File system     标志
 1      1049kB  211MB  210MB   primary   ext4            启动
 2      211MB   105GB  105GB   primary   ext4
 3      105GB   210GB  105GB   primary   ext4
 4      210GB   322GB  112GB   extended
 5      210GB   219GB  8590MB  logical   linux-swap(v1)
 6      219GB   220GB  1481MB  logical   ext4
 7      220GB   221GB  999MB   logical   fat32
 8      221GB   223GB  1999MB  logical

[root@localhost ~]#

步骤二：将/dev/sda8格式化为swap文件系统

[root@localhost ~]# ls /dev/sda8       //检查系统是否识别该分区
ls: 无法访问/dev/sda8: 没有那个文件或目录
[root@localhost ~]# partx -a /dev/sda  //刷新分区表
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
BLKPG: Device or resource busy
error adding partition 3
BLKPG: Device or resource busy
error adding partition 4
BLKPG: Device or resource busy
error adding partition 5
BLKPG: Device or resource busy
error adding partition 6
BLKPG: Device or resource busy
error adding partition 7
[root@localhost ~]# ls /dev/sda8
/dev/sda8
[root@localhost ~]# mkswap /dev/sda8   //格式化为swap文件系统
Setting up swapspace version 1, size = 1951740 KiB
no label, UUID=848ca15c-a03e-4e0b-9ac0-bfd6507d0b7e

步骤三：启用/dev/sda8分区，查看swap空间大小

[root@localhost ~]# swapon –s          //未启用之前，查看swap空间组成成员
Filename                                Type            Size    Used    Priority
/dev/sda5                               partition       8388600 0       -1
[root@localhost ~]# swapon /dev/sda8  //启用/dev/sda8交换分区
[root@localhost ~]# swapon –s          //启用之后，查看swap空间组成成员
Filename                                Type            Size    Used    Priority
/dev/sda5                               partition       8388600 0       -1
/dev/sda8                               partition       1951736 0       -2
[root@localhost ~]#

步骤四：停用/dev/sda8分区，查看swap空间大小

[root@localhost ~]# swapoff /dev/sda8   //停用/dev/sda8交换分区
[root@localhost ~]# swapon -s
Filename                                Type            Size    Used    Priority
/dev/sda5                               partition       8388600 0       -1
[root@localhost ~]#