centos7.0下增加swap分区大小

承接上篇文章扩容磁盘空间后增加根分区的大小后，来扩容swap分区的空间

检查当前的swap分区情况

# free -m

# free -g

[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:
Swap:
[root@localhost ~]#
[root@localhost ~]# free -g
              total        used        free      shared  buff/cache   available
Mem:
Swap:                                   

查看磁盘分区挂载情况：

# cat /etc/fstab

[root@localhost ~]# cat /etc/fstab 

#
# /etc/fstab
# Created by anaconda on Fri Feb  ::
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(), findfs(), mount() and/or blkid() for more info
#
/dev/mapper/centos-root /                       xfs     defaults
UUID=a3983c4b-cce5-47b8-b1f7-f9c7d177d034 /boot                   xfs     defaults
/dev/mapper/centos-swap swap                    swap    defaults
[root@localhost ~]# 

查看交换分区大小

# fdisk -l /dev/mapper/centos-swap

[root@localhost ~]# fdisk -l /dev/mapper/c
centos-root  centos-swap  control
[root@localhost ~]# fdisk -l /dev/mapper/centos-swap 

Disk /dev/mapper/centos-swap:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

查看逻辑卷

# lvdisplay

[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                hw5xxY-pk8O-tFdd-RWXj-Kjzd-YlXG-55aifc
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, -- :: +
  LV Status              available
  # open
  LV Size                115.00 GiB
  Current LE
  Segments
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to
  Block device           :

  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                Gjc4kX-XGS5-0H42-WVIJ-jllu-W9Ql-TQ7Je8
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, -- :: +
  LV Status              available
  # open
  LV Size                2.00 GiB
  Current LE
  Segments
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to
  Block device           :

[root@localhost ~]# 

新增分区

#fdisk /dev/sda

需要重启才能生效

#reboot

重启后查看硬盘信息

# lsblk

[root@localhost ~]# lsblk
NAME            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda               :      150G   disk
├─sda1            :      200M   part /boot
├─sda2            :       17G   part
│ ├─centos-root :      115G   lvm  /
│ └─centos-swap :        2G   lvm  [SWAP]
├─sda3            :      100G   part
│ └─centos-root :      115G   lvm  /
└─sda4            :     .8G   part
sr0              :        4G   rom  

分区格式化

# mkfs -t ext4 /dev/sda4

[root@localhost ~]# mkfs -t ext4 /dev/sda4
mke2fs 1.42. (-Dec-)
Filesystem label=
OS type: Linux
Block size= (log=)
Fragment size= (log=)
Stride= blocks, Stripe width= blocks
 inodes,  blocks
 blocks (5.00%) reserved for the super user
First data block=
Maximum filesystem blocks=
 block groups
 blocks per group,  fragments per group
 inodes per group
Superblock backups stored on blocks:
        , , , , , , , , ,
        , 

Allocating group tables: done
Writing inode tables: done
Creating journal ( blocks): done
Writing superblocks and filesystem accounting information: done 

创建物理卷

# pvcreate /dev/sda4

[root@localhost ~]# pvcreate /dev/sda4
WARNING: ext4 signature detected on /dev/sda4 at offset . Wipe it? [y/n]: y
  Wiping ext4 signature on /dev/sda4.
  Physical volume "/dev/sda4" successfully created

加入根分区的逻辑卷组

# vgextend centos /dev/sda3

查看确认

# vgdisplay

[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               149.79 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 117.00 GiB
  Free  PE / Size        / 32.79 GiB
  VG UUID               a27Boi-C0ue-9PCo-1rPZ-BsjW-9IRg-Woh4uX

卸载swap分区

# swapoff /dev/mapper/centos-swap

扩展swap逻辑卷

# lvextend  -L +2G /dev/mapper/centos-swap

[root@localhost ~]# swapoff /dev/mapper/centos-swap
[root@localhost ~]#
[root@localhost ~]# lvextend  -L +2G /dev/mapper/centos-swap
  Size of logical volume centos/swap changed from 2.00 GiB ( extents) to 4.00 GiB ( extents).
  Logical volume swap successfully resized.
[root@localhost ~]#
[root@localhost ~]# fdisk -l /dev/mapper/centos-swap 

Disk /dev/mapper/centos-swap:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes

[root@localhost ~]# 

格式化新swap分区

# mkswap /dev/mapper/centos-swap

[root@localhost ~]# mkswap /dev/mapper/centos-swap
mkswap: /dev/mapper/centos-swap: warning: wiping old swap signature.
Setting up swapspace version , size =  KiB
no label, UUID=05ed5220-b350-4bb1--f75dbe35b0ba

重新挂载swap分区

# swapon /dev/mapper/centos-swap

[root@localhost ~]# swapon /dev/mapper/centos-swap
[root@localhost ~]#
[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:
Swap:                             

重启系统验证

#reboot

# free -m

[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:
Swap:
[root@localhost ~]# 

至此swap分区扩容完毕

参考博客：

Linux swap扩容

https://www.cnblogs.com/rangle/p/9075370.html

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