swap交换分区
swap 是 linux 系统磁盘管理的一块特殊的分区，当实际的物理内存不足的时候，操作系统会从整个内存中，取出一部分暂时没在使用的内存，拿出来放到交换分区，从而提供给当前正在使用的程序，可以使用更多的内存。
使用 swap 分区的作用是，通过操作系统的调取，程序可以用到的实际内存，会远大于物理内存。
swap 分区大小，必须根据物理内存和硬盘容量来计算
-当你的物理内存小于 1G，必须使用 swap 提升内存使用量
-内存使用过多的应用程序，比如图像，视频等，必须用 swap 分区防止物理内存不足，造成软件崩溃。
-当你的电脑休眠，内存中的数据会放入 swap 交换分区中，当你的电脑恢复后，再从 swap 中读取数据，恢复软件正常工作
创建 swap 分区
centos7 系统，计算 swap 分区如下：
-内存小于2G, swap 分配和内存同样大小的空间
-内存大于2G， swap 也就分配2G空间
1.先给磁盘分一个区，得指定 swap 分区类型， fdisk /dev/sdc
2.针对磁盘分区进行格式化 mkswap /dev/sdc1
3.再来使用 swap 分区 swapon 开启交换空间 swapoff 关闭交换空间
swap 代码验证
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 660 2636 13 573 2968
Swap: 2047 0 2047root@ubuntu:~# fdisk -l | grep sdc
Disk /dev/sdc: 120 GiB, 128849018880 bytes, 251658240 sectors
/dev/sdc1 34 976562 976529 476.8M Linux filesystem
/dev/sdc2 978944 97656831 96677888 46.1G Linux filesystem第一种 GPT格式 磁盘分区 创建 swap 交换分区
# 进入创建分区磁盘
root@ubuntu:~# parted /dev/sdc
GNU Parted 3.4
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p # 打印磁盘分区信息
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: Number Start End Size File system Name Flags1 17.4kB 500MB 500MB ext4 primary2 501MB 50.0GB 49.5GB ntfs logical# 创建主分区
(parted) mkpart primary 50001 52000
(parted) p # 打印分区信息
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: Number Start End Size File system Name Flags1 17.4kB 500MB 500MB ext4 primary2 501MB 50.0GB 49.5GB ntfs logical3 50.0GB 52.0GB 1999MB primary# 创建 swap 交换分区
(parted) t
Partition number? 3
Flag to Invert? swap
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: Number Start End Size File system Name Flags1 17.4kB 500MB 500MB ext4 primary2 501MB 50.0GB 49.5GB ntfs logical3 50.0GB 52.0GB 1999MB primary swap(parted) q # 退出
Information: You may need to update /etc/fstab.root@ubuntu:~# fdisk -l | grep sdc
Disk /dev/sdc: 120 GiB, 128849018880 bytes, 251658240 sectors
/dev/sdc1 34 976562 976529 476.8M Linux filesystem
/dev/sdc2 978944 97656831 96677888 46.1G Linux filesystem
/dev/sdc3 97658880 101562367 3903488 1.9G Linux swap
root@ubuntu:~# parted /dev/sdc
GNU Parted 3.4
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: Number Start End Size File system Name Flags1 17.4kB 500MB 500MB ext4 primary2 501MB 50.0GB 49.5GB ntfs logical3 50.0GB 52.0GB 1999MB primary swap(parted) q
# 对 /dev/sdc3 分区进行 swap 格式化
root@ubuntu:~# mkswap /dev/sdc3
Setting up swapspace version 1, size = 1.9 GiB (1998581760 bytes)
no label, UUID=6afd7ed9-2ff8-4306-8721-9030287a5609
# 查看磁盘分区信息
root@ubuntu:~# parted /dev/sdc
GNU Parted 3.4
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: Number Start End Size File system Name Flags1 17.4kB 500MB 500MB ext4 primary2 501MB 50.0GB 49.5GB ntfs logical3 50.0GB 52.0GB 1999MB linux-swap(v1) primary swaproot@ubuntu:~# fdisk -l | grep sdc
Disk /dev/sdc: 120 GiB, 128849018880 bytes, 251658240 sectors
/dev/sdc1 34 976562 976529 476.8M Linux filesystem
/dev/sdc2 978944 97656831 96677888 46.1G Linux filesystem
/dev/sdc3 97658880 101562367 3903488 1.9G Linux swap第二中 MBR格式 磁盘分区 创建 swap 交换分区
root@ubuntu:~# fdisk -l | grep sd
Disk /dev/sda: 100 GiB, 107374182400 bytes, 209715200 sectors
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 1054719 1050624 513M EFI System
/dev/sda3 1054720 209713151 208658432 99.5G Linux filesystem
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk /dev/sdc: 120 GiB, 128849018880 bytes, 251658240 sectors
/dev/sdc1 34 976562 976529 476.8M Linux filesystem
/dev/sdc2 978944 97656831 96677888 46.1G Linux filesystem
/dev/sdc3 97658880 101562367 3903488 1.9G Linux swap
root@ubuntu:~# fdisk /dev/sdbWelcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.Command (m for help): p
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xf4813d41Command (m for help): n
Partition typep primary (0 primary, 0 extended, 4 free)e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-209715199, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-209715199, default 209715199): +500MCreated a new partition 1 of type 'Linux' and of size 500 MiB.Command (m for help): mHelp:DOS (MBR)a toggle a bootable flagb edit nested BSD disklabelc toggle the dos compatibility flagGenericd delete a partitionF list free unpartitioned spacel list known partition typesn add a new partitionp print the partition tablet change a partition typev verify the partition tablei print information about a partitionMiscm print this menuu change display/entry unitsx extra functionality (experts only)ScriptI load disk layout from sfdisk script fileO dump disk layout to sfdisk script fileSave & Exitw write table to disk and exitq quit without saving changesCreate a new labelg create a new empty GPT partition tableG create a new empty SGI (IRIX) partition tableo create a new empty DOS partition tables create a new empty Sun partition tableCommand (m for help): t
Selected partition 1
Hex code or alias (type L to list all): 82
Changed type of partition 'Linux' to 'Linux swap / Solaris'.Command (m for help): p
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xf4813d41Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 1026047 1024000 500M 82 Linux swap / Solaris# 把创建的 swap 交换分区写入磁盘
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
root@ubuntu:~# fdisk -l | grep sdb
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
/dev/sdb1 2048 1026047 1024000 500M 82 Linux swap / Solarisroot@ubuntu:~# lsblk -f | grep sdb
sdb
└─sdb1
# 对 /dev/sdb1 分区进行 swap 格式化
root@ubuntu:~# mkswap /dev/sdb1
Setting up swapspace version 1, size = 500 MiB (524283904 bytes)
no label, UUID=e353971b-a7cf-488d-9b1c-db22e2958411
root@ubuntu:~# lsblk -f | grep sdb
sdb
└─sdb1 swap 1 e353971b-a7cf-488d-9b1c-db22e2958411 root@ubuntu:~# fdisk -l | grep sd
Disk /dev/sda: 100 GiB, 107374182400 bytes, 209715200 sectors
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 1054719 1050624 513M EFI System
/dev/sda3 1054720 209713151 208658432 99.5G Linux filesystem
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
/dev/sdb1 2048 1026047 1024000 500M 82 Linux swap / Solaris
Disk /dev/sdc: 120 GiB, 128849018880 bytes, 251658240 sectors
/dev/sdc1 34 976562 976529 476.8M Linux filesystem
/dev/sdc2 978944 97656831 96677888 46.1G Linux filesystem
/dev/sdc3 97658880 101562367 3903488 1.9G Linux swap# 如何使用 swap 交换分区
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 592 2687 13 591 3036
Swap: 2047 0 2047root@ubuntu:~# sw
swaplabel swapoff swapon switcherooctl switch_root # 开启 /dev/sdb1 设备的 swap 交换分区 swapon /dev/sdb1
root@ubuntu:~# swapon /dev/sdb1
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 588 2690 13 591 3040
Swap: 2547 0 2547# 开启 /dev/sdc3 设备的 swap 交换分区 swapon /dev/sdc3
root@ubuntu:~# swapon /dev/sdc3
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 591 2687 13 591 3036
Swap: 4453 0 4453# 关闭 /dev/sdb1 设备的 swap 交换分区 swapoff /dev/sdb1
# 关闭 /dev/sdc3 设备的 swap 交换分区 swapoff /dev/sdc3root@ubuntu:~# swapoff /dev/sdb1
root@ubuntu:~# swapoff /dev/sdc3
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 594 2684 13 591 3034
Swap: 2047 0 2047
buffers 和 cached解析
buffers 缓冲区 buffers 是给写入数据加速使用的
cached 缓存 cached 是用于读取数据时，加速使用的。
cached 表示把数据从磁盘上读取出来，保存在内存中，再次读取的时候，不再去硬盘上拉取数据，直接从内存中读取，加速查找。
buffers 表示在写入磁盘数据的时候，把分散的操作临时保存到内存中，达到一定的数量之后，集中写入到磁盘，减少磁盘碎片，加速数据查找，减少磁头的反复的寻道时间。
buff 和 cache 的作用总结
-buffers 和 cached 都是基于内存的存储中间层
cached 解决的时间问题，加速读取的过程
buffers 解决空间存储问题，给数据一个临时存放的区域。
cached 利用内存的高速读写特性，
buffers 利用了内存的存储空间特性。
#########
我的内存被吃了，无辜提示内存不足了怎么办，但是在 cache,buff 中又看到大量的内存，如何释放
解决方案：
1. 释放cache 的命令
echo 1 > /proc/sys/vm/drop_caches 也可以用 sysctl -w vm.drop_caches=1 命令
命令解释：
"echo 1" 是释放 buff 的一个命令参数，把 "1"写入到 /proc/sys/vm/drop_caches 文件中， "1" 代表为真，让删除缓存生效。
2.清除目录缓存和 inodes 命令
echo 2 > /proc/sys/vm/drop_caches 也可以用 sysctl -w vm.drop_caches=2 命令
3. 清除内存页的缓存
echo 3 > /proc/sys/vm/drop_caches 也可以用 sysctl -w vm.drop_caches=3 命令
以上三种方式都是临时释放缓存的命令，
要永久生效 vim /etc/sysctl.conf 将要清除的命令写入到这个文件中
除了以上3个命令，还可以清理文件系统缓存，使用 sync 命令，可以用于清理僵尸进程(就是主进程挂了，剩下的子进程就群龙无首，变僵尸进程了)
sync 的作用：将内存缓冲区的数据，写入到磁盘中
实战
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 599 2252 13 1019 3022
Swap: 2047 0 2047
root@ubuntu:~# echo 1 > /proc/sys/vm/drop_caches # 1 代表 cache
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 595 2985 13 289 3028
Swap: 2047 0 2047# 同步sync 将内存中缓冲区的数据写入到磁盘中
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 587 2978 13 303 3036
Swap: 2047 0 2047
root@ubuntu:~# sync
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 590 2975 13 303 3033
Swap: 2047 0 2047root@ubuntu:~# swapon /dev/sdc3
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 591 2974 13 304 3032
Swap: 3953 0 3953
root@ubuntu:~# swapoff /dev/sdc3
root@ubuntu:~# free -mtotal used free shared buff/cache available
Mem: 3870 591 2974 13 304 3033
Swap: 2047 0 2047
root@ubuntu:~# vim /etc/sysctl.conf
root@ubuntu:~# cat /etc/sysctl.conf
#
# /etc/sysctl.conf - Configuration file for setting system variables
# See /etc/sysctl.d/ for additional system variables.
# See sysctl.conf (5) for information.
##kernel.domainname = example.com# Uncomment the following to stop low-level messages on console
#kernel.printk = 3 4 1 3###################################################################
# Functions previously found in netbase
## Uncomment the next two lines to enable Spoof protection (reverse-path filter)
# Turn on Source Address Verification in all interfaces to
# prevent some spoofing attacks
#net.ipv4.conf.default.rp_filter=1
#net.ipv4.conf.all.rp_filter=1# Uncomment the next line to enable TCP/IP SYN cookies
# See http://lwn.net/Articles/277146/
# Note: This may impact IPv6 TCP sessions too
#net.ipv4.tcp_syncookies=1# Uncomment the next line to enable packet forwarding for IPv4
#net.ipv4.ip_forward=1# Uncomment the next line to enable packet forwarding for IPv6
# Enabling this option disables Stateless Address Autoconfiguration
# based on Router Advertisements for this host
#net.ipv6.conf.all.forwarding=1###################################################################
# Additional settings - these settings can improve the network
# security of the host and prevent against some network attacks
# including spoofing attacks and man in the middle attacks through
# redirection. Some network environments, however, require that these
# settings are disabled so review and enable them as needed.
#
# Do not accept ICMP redirects (prevent MITM attacks)
#net.ipv4.conf.all.accept_redirects = 0
#net.ipv6.conf.all.accept_redirects = 0
# _or_
# Accept ICMP redirects only for gateways listed in our default
# gateway list (enabled by default)
# net.ipv4.conf.all.secure_redirects = 1
#
# Do not send ICMP redirects (we are not a router)
#net.ipv4.conf.all.send_redirects = 0
#
# Do not accept IP source route packets (we are not a router)
#net.ipv4.conf.all.accept_source_route = 0
#net.ipv6.conf.all.accept_source_route = 0
#
# Log Martian Packets
#net.ipv4.conf.all.log_martians = 1
####################################################################
# Magic system request Key
# 0=disable, 1=enable all, >1 bitmask of sysrq functions
# See https://www.kernel.org/doc/html/latest/admin-guide/sysrq.html
# for what other values do
#kernel.sysrq=438开机自动挂载与磁盘容量统计
#######
开机自动挂载文件
1.由于 mount 命令直接输入是临时生效，下次重启，挂载的设备分区就无法使用了，因此就出现了一个 /etc/fstab 文件，存放系统一些静态文件的地方，主要是系统启动的时候，系统默认的读取这个文件的信息，将指定的挂载点，进行挂载。
# 通过 mount -a 命令，可以读取 /etc/fstab 文件所有的挂载情况
/dev/sdc2 /mnt ntfs defaults 0 0
解析如上的参数：
第一列："/dev/sdc2" 是设备的名字，可以是文件系统，也可以是设备名称，NFS 远程网络文件系统。
mount /dev/sdc2 /mnt # 第一种写法
mount 192.168.11.15:/home/ntfs /mnt/ -o nolock
# 把本地的 /mnt 文件夹挂载到 ntfs 文件系统上，且不加锁
第二列：挂载点
就是自己创建的一个目录，是一个已经存在的目录
第三列：linux系统能够支持的文件系统类型
ext3 ext4 nfs swap ntfs xfs
第四列：挂载的功能选项，有很多，默认使用 defaults
第五列：dump
表示将整个文件夹内容备份，一般不对挂载点备份，默认都是0，
第六列：fsck 磁盘检查
默认都是0，不对磁盘进行检查，但是根文件系统，默认是检查的，vim /etc/fstab 在最后添加一行
/dev/sdb5 /mnt xfs defaults 0 0 (centos7)
=======
df 命令，检查挂载点的使用情况
df 命令的实际案例
可使用的命令参数
-h 显示 kb mb单位大小
-i 显示 inode 数量
========
du 命令，显示磁盘空间大小的命令，文件大小的命令
linux 文件存储最小单位是 4k,也就是8个扇区
du -h 显示文件大小 kb mb 为显示单位
du -h * 显示当前目录所有文件的大小
du -a 显示目录中所有文件的大小
du -ah * 显示所有文件的大小信息
统计 /opt/目录下第1层目录大小
du -ah --max-depth=1 /opt/ # '--max-depth=1' 就是指定文件夹深度的参数
显示出当前目录下所有文件，除了 .conf文件的大小 参数作用是，指定排除文件名的作用
du -ah --exclude='*.conf' /opt/
实战
# 在该文件(/etc/fstab)最后一行添加如下一行 就表示永久挂载 /dev/sdc2 这个设备了
root@ubuntu:~# vim /etc/fstab
root@ubuntu:~# tail -1 /etc/fstab
/dev/sdc2 /mnt ntfs defaults 0 0root@ubuntu:~# vim /etc/fstab
root@ubuntu:~# cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sda3 during installation
UUID=f4b2aa80-fa0b-417e-ab7b-fa27caf2f921 / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda2 during installation
UUID=4D72-6786 /boot/efi vfat umask=0077 0 1
/swapfile none swap sw 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0# 目录挂载以后，源目录的内容将被隐藏
root@ubuntu:~# touch /mnt/超哥带你学linux.txt
root@ubuntu:~# ls /mnt/
超哥带你学linux.txt# 挂载以后，挂载目录将显示 /dev/sdc2 设备上的内容
root@ubuntu:~# mount /dev/sdc2 /mnt
root@ubuntu:~# ls /mnt/
test.txtroot@ubuntu:~# umount /mnt
root@ubuntu:~# ls /mnt/
超哥带你学linux.txt# 已经挂载文件的使用情况
root@ubuntu:~# df -h
Filesystem Size Used Avail Use% Mounted on
tmpfs 388M 1.9M 386M 1% /run
/dev/sda3 98G 11G 83G 12% /
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/sda2 512M 6.1M 506M 2% /boot/efi
tmpfs 388M 72K 387M 1% /run/user/126
tmpfs 388M 56K 387M 1% /run/user/0
/dev/sdc2 47G 66M 47G 1% /mnt# 已经挂载文件的使用情况 再加一个大写的T参数，可以显示文件系统类型
root@ubuntu:~# df -hT
Filesystem Type Size Used Avail Use% Mounted on
tmpfs tmpfs 388M 1.9M 386M 1% /run
/dev/sda3 ext4 98G 11G 83G 12% /
tmpfs tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs tmpfs 5.0M 4.0K 5.0M 1% /run/lock
/dev/sda2 vfat 512M 6.1M 506M 2% /boot/efi
tmpfs tmpfs 388M 72K 387M 1% /run/user/126
tmpfs tmpfs 388M 56K 387M 1% /run/user/0
/dev/sdc2 fuseblk 47G 66M 47G 1% /mnt# -i 参数 显示 inode 数量
root@ubuntu:~# df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
tmpfs 495434 1134 494300 1% /run
/dev/sda3 6520832 202164 6318668 4% /
tmpfs 495434 1 495433 1% /dev/shm
tmpfs 495434 4 495430 1% /run/lock
/dev/sda2 0 0 0 - /boot/efi
tmpfs 99086 83 99003 1% /run/user/126
tmpfs 99086 54 99032 1% /run/user/0
/dev/sdc2 48304176 20 48304156 1% /mntroot@ubuntu:~# df -i -h
Filesystem Inodes IUsed IFree IUse% Mounted on
tmpfs 484K 1.2K 483K 1% /run
/dev/sda3 6.3M 198K 6.1M 4% /
tmpfs 484K 1 484K 1% /dev/shm
tmpfs 484K 4 484K 1% /run/lock
/dev/sda2 0 0 0 - /boot/efi
tmpfs 97K 83 97K 1% /run/user/126
tmpfs 97K 54 97K 1% /run/user/0
/dev/sdc2 47M 20 47M 1% /mnt# 显示当前目录指定文件名的大小
root@ubuntu:/tmp# du -h hehe.txt
4.0K hehe.txt
root@ubuntu:/tmp# du -h /opt/*
4.0K /opt/akdxfhfnejeikjaaksdklf
0 /opt/aklf
4.0K /opt/happy2
# 显示所有文件的大小信息
root@ubuntu:/tmp# du -ah /etc/* 所有文件大小都能被4整除
4.0K /etc/acpi/asus-keyboard-backlight.sh
4.0K /etc/acpi/asus-wireless.sh
4.0K /etc/acpi/events/lenovo-undock
4.0K /etc/acpi/events/asus-wireless-off
4.0K /etc/acpi/events/asus-keyboard-backlight-down
4.0K /etc/acpi/events/asus-keyboard-backlight-up
4.0K /etc/acpi/events/thinkpad-cmos
4.0K /etc/acpi/events/ibm-wireless
4.0K /etc/acpi/events/asus-wireless-on
4.0K /etc/acpi/events/tosh-wireless
36K /etc/acpi/events
4.0K /etc/acpi/ibm-wireless.sh
4.0K /etc/acpi/tosh-wireless.sh# 统计 /opt/目录下第1层目录大小
root@ubuntu:/tmp# du -ah --max-depth=1 /opt/
0 /opt/aklf
4.0K /opt/happy2
4.0K /opt/akdxfhfnejeikjaaksdklf
12K /opt/# 统计 /opt/目录下第2层目录大小
root@ubuntu:/tmp# du -ah --max-depth=2 /opt/
0 /opt/aklf
4.0K /opt/happy2
0 /opt/akdxfhfnejeikjaaksdklf/我是超哥
4.0K /opt/akdxfhfnejeikjaaksdklf
12K /opt/# 显示出当前目录下所有文件，除了 .conf文件的大小 参数作用是，指定排除文件名的作用
root@ubuntu:/tmp# du -ah --exclude='*.conf' /opt/
0 /opt/aklf
4.0K /opt/happy2
0 /opt/akdxfhfnejeikjaaksdklf/我是超哥
4.0K /opt/akdxfhfnejeikjaaksdklf
12K /opt/root@ubuntu:~# mount -l
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=1943452k,nr_inodes=485863,mode=755,inode64)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=396348k,mode=755,inode64)
/dev/sda3 on / type ext4 (rw,relatime,errors=remount-ro)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k,inode64)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=29,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=30431)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
ramfs on /run/credentials/systemd-sysusers.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700)
/var/lib/snapd/snaps/bare_5.snap on /snap/bare/5 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core_16574.snap on /snap/core/16574 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core_16202.snap on /snap/core/16202 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core20_2105.snap on /snap/core20/2105 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core20_2182.snap on /snap/core20/2182 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core22_1033.snap on /snap/core22/1033 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/firefox_631.snap on /snap/firefox/631 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/firefox_3779.snap on /snap/firefox/3779 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/snap-store_959.snap on /snap/snap-store/959 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-42-2204_141.snap on /snap/gnome-42-2204/141 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/snap-store_557.snap on /snap/snap-store/557 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core22_1122.snap on /snap/core22/1122 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gtk-common-themes_1535.snap on /snap/gtk-common-themes/1535 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-3-38-2004_143.snap on /snap/gnome-3-38-2004/143 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/dev/sda3 on /var/snap/firefox/common/host-hunspell type ext4 (ro,noexec,noatime,errors=remount-ro)
/var/lib/snapd/snaps/gtk-common-themes_1519.snap on /snap/gtk-common-themes/1519 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-3-38-2004_76.snap on /snap/gnome-3-38-2004/76 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/dev/sda2 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /run/user/126 type tmpfs (rw,nosuid,nodev,relatime,size=396344k,nr_inodes=99086,mode=700,uid=126,gid=132,inode64)
gvfsd-fuse on /run/user/126/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=126,group_id=132)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=396344k,nr_inodes=99086,mode=700,inode64)
root@ubuntu:~# lsblk -f | grep sd
sda
├─sda1
├─sda2 vfat FAT32 4D72-6786 505.9M 1% /boot/efi
└─sda3 ext4 1.0 f4b2aa80-fa0b-417e-ab7b-fa27caf2f921 82.2G 11% /var/snap/firefox/common/host-hunspell
sdb
└─sdb1 swap 1 e353971b-a7cf-488d-9b1c-db22e2958411
sdc
├─sdc1 ext4 1.0 52572ca0-5fbf-4604-b1df-e887a0af43dd
├─sdc2 ntfs 0B145F533BB37153
└─sdc3 swap 1 6afd7ed9-2ff8-4306-8721-9030287a5609 root@ubuntu:~# mount /dev/sdc2 /mnt
root@ubuntu:~# lsblk -f | grep sd
sda
├─sda1
├─sda2 vfat FAT32 4D72-6786 505.9M 1% /boot/efi
└─sda3 ext4 1.0 f4b2aa80-fa0b-417e-ab7b-fa27caf2f921 82.2G 11% /var/snap/firefox/common/host-hunspell
sdb
└─sdb1 swap 1 e353971b-a7cf-488d-9b1c-db22e2958411
sdc
├─sdc1 ext4 1.0 52572ca0-5fbf-4604-b1df-e887a0af43dd
├─sdc2 ntfs 0B145F533BB37153 46G 0% /mnt
└─sdc3 swap 1 6afd7ed9-2ff8-4306-8721-9030287a5609 root@ubuntu:~# mount -l
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,nosuid,relatime,size=1943452k,nr_inodes=485863,mode=755,inode64)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=396348k,mode=755,inode64)
/dev/sda3 on / type ext4 (rw,relatime,errors=remount-ro)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k,inode64)
cgroup2 on /sys/fs/cgroup type cgroup2 (rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=29,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=30431)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
fusectl on /sys/fs/fuse/connections type fusectl (rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
ramfs on /run/credentials/systemd-sysusers.service type ramfs (ro,nosuid,nodev,noexec,relatime,mode=700)
/var/lib/snapd/snaps/bare_5.snap on /snap/bare/5 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core_16574.snap on /snap/core/16574 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core_16202.snap on /snap/core/16202 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core20_2105.snap on /snap/core20/2105 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core20_2182.snap on /snap/core20/2182 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core22_1033.snap on /snap/core22/1033 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/firefox_631.snap on /snap/firefox/631 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/firefox_3779.snap on /snap/firefox/3779 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/snap-store_959.snap on /snap/snap-store/959 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-42-2204_141.snap on /snap/gnome-42-2204/141 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/snap-store_557.snap on /snap/snap-store/557 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/core22_1122.snap on /snap/core22/1122 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gtk-common-themes_1535.snap on /snap/gtk-common-themes/1535 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-3-38-2004_143.snap on /snap/gnome-3-38-2004/143 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/dev/sda3 on /var/snap/firefox/common/host-hunspell type ext4 (ro,noexec,noatime,errors=remount-ro)
/var/lib/snapd/snaps/gtk-common-themes_1519.snap on /snap/gtk-common-themes/1519 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/var/lib/snapd/snaps/gnome-3-38-2004_76.snap on /snap/gnome-3-38-2004/76 type squashfs (ro,nodev,relatime,errors=continue,threads=single,x-gdu.hide)
/dev/sda2 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,nosuid,nodev,noexec,relatime)
tmpfs on /run/user/126 type tmpfs (rw,nosuid,nodev,relatime,size=396344k,nr_inodes=99086,mode=700,uid=126,gid=132,inode64)
gvfsd-fuse on /run/user/126/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=126,group_id=132)
tmpfs on /run/user/0 type tmpfs (rw,nosuid,nodev,relatime,size=396344k,nr_inodes=99086,mode=700,inode64)
/dev/sdc2 on /mnt type fuseblk (rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096) # 可以看到 /dev/sdc2 挂载的内容
