1、首先通过df -lh命令查看虚拟机的根目录下是否有足够大的硬盘空间。
[email?protected]:~# df -h
Filesystem??????????????????? Size? Used Avail Use% Mounted on
udev????????????????????????? 7.9G???? 0? 7.9G?? 0% /dev
tmpfs???????????????????????? 1.6G?? 18M? 1.6G?? 2% /run
/dev/mapper/eve--ng--vg-root? 196G? 8.1G? 179G?? 5% /
tmpfs???????????????????????? 7.9G???? 0? 7.9G?? 0% /dev/shm
tmpfs???????????????????????? 5.0M???? 0? 5.0M?? 0% /run/lock
tmpfs???????????????????????? 7.9G???? 0? 7.9G?? 0% /sys/fs/cgroup
/dev/sda1???????????????????? 472M?? 83M? 365M? 19% /boot
2、通过free -m命令查看当前交换分区的大小，当前系统的交换分区为0.95GB。
[email?protected]:~# free -m
????????????? total??????? used??????? free????? shared? buff/cache?? available
Mem:????????? 16045???????? 418?????? 15237????????? 26???????? 389?????? 15261
Swap:?????????? 979?????????? 0???????? 979
3、通过dd if=/dev/zero of=/swap-1 bs=1024M count=20，在系统根目录下创建一个名字为swap-1的20GB交换文件，当然如果20GB不够用可以通过调整count后面的数字来创建更大的交换文件。这个过程稍微多等一下。
[email?protected]:~# dd if=/dev/zero of=/swap-1 bs=1024M count=20
20+0 records in
20+0 records out
21474836480 bytes (21 GB,20 GiB) copied,21.194 s,1.0 GB/s
通过cd /和ls命令查看交换文件是否已经建好。
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?4、通过mkswap /swap-1和swapon /swap-1命令对刚才创建的文件格式进行转换并挂载
[email?protected]:/# mkswap /swap-1
mkswap: /swap-1: warning: wiping old swap signature.
Setting up swapspace version 1,size = 20 GiB (21474832384 bytes)
no label,UUID=6d581f29-b368-4dd6-83f2-74b34ab44a2c
[email?protected]:/# swapon /swap-1
swapon: /swap-1: insecure permissions 0777,0600 suggested.
5、通过swapon -s和free -m命令查看交换文件是否挂载成功和查看系统当前交换分区的大小，下图中的交换分区大小已经从原始的0.9G增加到0.9+20总计21GB大小
[email?protected]:/# swapon -s
Filename??????????????????????????????? Type??????????? Size??? Used??? Priority
/dev/dm-1?????????????????????????????? partition?????? 1003516 1260??? -1
/swap-1???????????????????????????????? file??????????? 20971516??????? 0?????? -2
[email?protected]:/# free -m
????????????? total??????? used??????? free????? shared? buff/cache?? available
Mem:????????? 16045???????? 430??????? 1167????????? 26?????? 14448?????? 15180
Swap:???????? 21459?????????? 1?????? 21458
6、通过WinScp工具对/etc下的fstab文件进行修改，以达到系统开机时自动挂载刚才创建好的交换文件，当然也可以在虚拟机中通过vim的方式进行修改。
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?在fstab文件中增加一行/swap-1 swap swap default 0 0并保存文件
7、通过shutdown -r now重启虚拟机，并通过free -m和swapon -s来验证创建好的交换文件是否自动挂载实现对交换分区的扩容。
[email?protected]:~# free -m
????????????? total??????? used??????? free????? shared? buff/cache?? available
Mem:????????? 16045???????? 405?????? 15271????????? 27???????? 368?????? 15282
Swap:???????? 21459?????????? 0?????? 21459
[email?protected]:~#
[email?protected]:~# swapon -s
Filename??????????????????????????????? Type??????????? Size??? Used??? Priority
/swap-1???????????????????????????????? file??????????? 20971516??????? 0?????? -1
/dev/dm-1?????????????????????????????? partition?????? 1003516 0?????? -2
[email?protected]:~#
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跟着EmulatedLab学习中！
