文件系统常用工具实战篇
文件系统常用工具实战篇
作者：尹正杰
版权声明：原创作品，谢绝转载！否则将追究法律责任。
本篇博客主要介绍df,du,dd三个命令的使用案例。
一.已挂载文件系统空间占用等信息的查看工具-df
1>.查看df命令的帮助信息
[root@yinzhengjie.com ~]# df --help Usage: df [OPTION]... [FILE]... Show information about the file system on which each FILE resides, or all file systems by default. Mandatory arguments to long options are mandatory for short options too. -a, --all include pseudo, duplicate, inaccessible file systems -B, --block-size=SIZE scale sizes by SIZE before printing them; e.g., '-BM' prints sizes in units of 1,048,576 bytes; see SIZE format below --direct show statistics for a file instead of mount point --total produce a grand total -h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G) -H, --si likewise, but use powers of 1000 not 1024 -i, --inodes list inode information instead of block usage -k like --block-size=1K -l, --local limit listing to local file systems --no-sync do not invoke sync before getting usage info (default) --output[=FIELD_LIST] use the output format defined by FIELD_LIST, or print all fields if FIELD_LIST is omitted. -P, --portability use the POSIX output format --sync invoke sync before getting usage info -t, --type=TYPE limit listing to file systems of type TYPE -T, --print-type print file system type -x, --exclude-type=TYPE limit listing to file systems not of type TYPE -v (ignored) --help display this help and exit --version output version information and exit Display values are in units of the first available SIZE from --block-size, and the DF_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables. Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set). SIZE is an integer and optional unit (example: 10M is 10*1024*1024). Units are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000). FIELD_LIST is a comma-separated list of columns to be included. Valid field names are: 'source', 'fstype', 'itotal', 'iused', 'iavail', 'ipcent', 'size', 'used', 'avail', 'pcent', 'file' and 'target' (see info page). GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'df invocation' [root@yinzhengjie.com ~]#
2>.df命令默认以字节形式显示
[root@yinzhengjie.com ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/centos-root 524032000 3589332 520442668 1% / devtmpfs 2001028 0 2001028 0% /dev tmpfs 2013192 0 2013192 0% /dev/shm tmpfs 2013192 11936 2001256 1% /run tmpfs 2013192 0 2013192 0% /sys/fs/cgroup /dev/sdb5 103080888 61468 97760156 1% /mnt/sdb5 /dev/sdc2 209612800 33008 209579792 1% /home /dev/sda2 1038336 135368 902968 14% /boot /dev/mapper/centos-yinzhengjie 1621224000 458632 1620765368 1% /yinzhengjie /dev/loop0 999320 2572 927936 1% /mnt/ext4 tmpfs 402640 0 402640 0% /run/user/0 [root@yinzhengjie.com ~]#
3>.以1000为单位显示磁盘使用空间
[root@yinzhengjie.com ~]# df -H Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 537G 3.7G 533G 1% / devtmpfs 2.1G 0 2.1G 0% /dev tmpfs 2.1G 0 2.1G 0% /dev/shm tmpfs 2.1G 13M 2.1G 1% /run tmpfs 2.1G 0 2.1G 0% /sys/fs/cgroup /dev/sdb5 106G 63M 101G 1% /mnt/sdb5 /dev/sdc2 215G 34M 215G 1% /home /dev/sda2 1.1G 139M 925M 14% /boot /dev/mapper/centos-yinzhengjie 1.7T 470M 1.7T 1% /yinzhengjie /dev/loop0 1.1G 2.7M 951M 1% /mnt/ext4 tmpfs 413M 0 413M 0% /run/user/0 [root@yinzhengjie.com ~]#
4>.人性化可读方式显示(以1024为单位显示)
[root@yinzhengjie.com ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 500G 3.5G 497G 1% / devtmpfs 2.0G 0 2.0G 0% /dev tmpfs 2.0G 0 2.0G 0% /dev/shm tmpfs 2.0G 12M 2.0G 1% /run tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup /dev/sdb5 99G 61M 94G 1% /mnt/sdb5 /dev/sdc2 200G 33M 200G 1% /home /dev/sda2 1014M 133M 882M 14% /boot /dev/mapper/centos-yinzhengjie 1.6T 448M 1.6T 1% /yinzhengjie /dev/loop0 976M 2.6M 907M 1% /mnt/ext4 tmpfs 394M 0 394M 0% /run/user/0 [root@yinzhengjie.com ~]#
5>.显示文件系统类型
[root@yinzhengjie.com ~]# df -T Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/mapper/centos-root xfs 524032000 3589100 520442900 1% / devtmpfs devtmpfs 2001028 0 2001028 0% /dev tmpfs tmpfs 2013192 0 2013192 0% /dev/shm tmpfs tmpfs 2013192 11936 2001256 1% /run tmpfs tmpfs 2013192 0 2013192 0% /sys/fs/cgroup /dev/sdb5 ext4 103080888 61468 97760156 1% /mnt/sdb5 /dev/sdc2 xfs 209612800 33008 209579792 1% /home /dev/sda2 xfs 1038336 135368 902968 14% /boot /dev/mapper/centos-yinzhengjie xfs 1621224000 458632 1620765368 1% /yinzhengjie /dev/loop0 ext4 999320 2572 927936 1% /mnt/ext4 tmpfs tmpfs 402640 0 402640 0% /run/user/0 [root@yinzhengjie.com ~]#
6>.显示inode信息
[root@yinzhengjie.com ~]# df -i Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/centos-root 262144000 114414 262029586 1% / devtmpfs 500257 466 499791 1% /dev tmpfs 503298 1 503297 1% /dev/shm tmpfs 503298 1379 501919 1% /run tmpfs 503298 16 503282 1% /sys/fs/cgroup /dev/sdb5 6553600 12 6553588 1% /mnt/sdb5 /dev/sdc2 104857600 8 104857592 1% /home /dev/sda2 524288 326 523962 1% /boot /dev/mapper/centos-yinzhengjie 162201600 1800 162199800 1% /yinzhengjie /dev/loop0 65536 13 65523 1% /mnt/ext4 tmpfs 503298 1 503297 1% /run/user/0 [root@yinzhengjie.com ~]#
7>.以Posix兼容的格式输出
[root@yinzhengjie.com ~]# df -P #在CentOS 6.x及之前的版本该命令需要使用"-P"参数，以防止第一列名称过长而导致一行内容分两行的形式显示，CentOS 7.x的df命令貌似默认就有"-P"功能。 Filesystem 1024-blocks Used Available Capacity Mounted on /dev/mapper/centos-root 524032000 3589132 520442868 1% / devtmpfs 2001028 0 2001028 0% /dev tmpfs 2013192 0 2013192 0% /dev/shm tmpfs 2013192 12008 2001184 1% /run tmpfs 2013192 0 2013192 0% /sys/fs/cgroup /dev/sdb5 103080888 61468 97760156 1% /mnt/sdb5 /dev/sdc2 209612800 33008 209579792 1% /home /dev/sda2 1038336 135368 902968 14% /boot /dev/mapper/centos-yinzhengjie 1621224000 1398664 1619825336 1% /yinzhengjie /dev/loop0 999320 2572 927936 1% /mnt/ext4 tmpfs 402640 0 402640 0% /run/user/0 /dev/loop1 939512 939512 0 100% /mnt/cdrom /dev/loop2 939512 939512 0 100% /mnt/centos [root@yinzhengjie.com ~]#
二.查看某目录总体空间占用状态工具-du
1>.查看du命令的帮助信息
[root@yinzhengjie.com ~]# du --help Usage: du [OPTION]... [FILE]... or: du [OPTION]... --files0-from=F Summarize disk usage of each FILE, recursively for directories. Mandatory arguments to long options are mandatory for short options too. -0, --null end each output line with 0 byte rather than newline -a, --all write counts for all files, not just directories --apparent-size print apparent sizes, rather than disk usage; although the apparent size is usually smaller, it may be larger due to holes in ('sparse') files, internal fragmentation, indirect blocks, and the like -B, --block-size=SIZE scale sizes by SIZE before printing them; e.g., '-BM' prints sizes in units of 1,048,576 bytes; see SIZE format below -b, --bytes equivalent to '--apparent-size --block-size=1' -c, --total produce a grand total -D, --dereference-args dereference only symlinks that are listed on the command line -d, --max-depth=N print the total for a directory (or file, with --all) only if it is N or fewer levels below the command line argument; --max-depth=0 is the same as --summarize --files0-from=F summarize disk usage of the NUL-terminated file names specified in file F; if F is -, then read names from standard input -H equivalent to --dereference-args (-D) -h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G) --inodes list inode usage information instead of block usage -k like --block-size=1K -L, --dereference dereference all symbolic links -l, --count-links count sizes many times if hard linked -m like --block-size=1M -P, --no-dereference don't follow any symbolic links (this is the default) -S, --separate-dirs for directories do not include size of subdirectories --si like -h, but use powers of 1000 not 1024 -s, --summarize display only a total for each argument -t, --threshold=SIZE exclude entries smaller than SIZE if positive, or entries greater than SIZE if negative --time show time of the last modification of any file in the directory, or any of its subdirectories --time=WORD show time as WORD instead of modification time: atime, access, use, ctime or status --time-style=STYLE show times using STYLE, which can be: full-iso, long-iso, iso, or +FORMAT; FORMAT is interpreted like in 'date' -X, --exclude-from=FILE exclude files that match any pattern in FILE --exclude=PATTERN exclude files that match PATTERN -x, --one-file-system skip directories on different file systems --help display this help and exit --version output version information and exit Display values are in units of the first available SIZE from --block-size, and the DU_BLOCK_SIZE, BLOCK_SIZE and BLOCKSIZE environment variables. Otherwise, units default to 1024 bytes (or 512 if POSIXLY_CORRECT is set). SIZE is an integer and optional unit (example: 10M is 10*1024*1024). Units are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000). GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'du invocation' [root@yinzhengjie.com ~]#
2>.默认查看当前目录下的所有目录(包括隐藏目录)总体空间占用状态
[root@yinzhengjie.com ~]# ll -aR .: total 52 dr-xr-x---. 4 root root 199 May 28 18:53 . dr-xr-xr-x. 18 root root 243 Jan 20 04:20 .. -rw-------. 1 root root 11187 May 28 18:06 .bash_history -rw-r--r--. 1 root root 18 Dec 29 2013 .bash_logout -rw-r--r--. 1 root root 176 Dec 29 2013 .bash_profile -rw-r--r--. 1 root root 271 May 16 14:19 .bashrc -rw-r--r--. 1 root root 100 Dec 29 2013 .cshrc -rw------- 1 root root 1499 May 18 11:25 .mysql_history drwxr----- 3 root root 19 May 15 20:09 .pki -rw------- 1 root root 87 May 15 23:56 .rediscli_history -rw-r--r--. 1 root root 129 Dec 29 2013 .tcshrc drwxr-xr-x 2 root root 45 May 28 18:53 test -rw------- 1 root root 9491 May 28 17:46 .viminfo ./.pki: total 0 drwxr----- 3 root root 19 May 15 20:09 . dr-xr-x---. 4 root root 199 May 28 18:53 .. drwxr----- 2 root root 6 May 15 20:09 nssdb ./.pki/nssdb: total 0 drwxr----- 2 root root 6 May 15 20:09 . drwxr----- 3 root root 19 May 15 20:09 .. ./test: total 8 drwxr-xr-x 2 root root 45 May 28 18:53 . dr-xr-x---. 4 root root 199 May 28 18:53 .. -rw-r--r-- 1 root root 64 May 7 03:10 dpt -rw-r--r-- 1 root root 408 May 16 14:19 random_encryption.sh [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# du 8 ./test 0 ./.pki/nssdb 0 ./.pki 60 . [root@yinzhengjie.com ~]#
3>.指定查看路径下所有目录总体空间占用状态
[root@yinzhengjie.com ~]# du /etc/ 72 /etc/grub.d 0 /etc/terminfo 12 /etc/skel 0 /etc/alternatives 0 /etc/chkconfig.d 8 /etc/libnl 40 /etc/rc.d/init.d 0 /etc/rc.d/rc0.d 0 /etc/rc.d/rc1.d 0 /etc/rc.d/rc2.d 0 /etc/rc.d/rc3.d 0 /etc/rc.d/rc4.d 0 /etc/rc.d/rc5.d 0 /etc/rc.d/rc6.d 44 /etc/rc.d 100 /etc/pam.d 4 /etc/depmod.d 0 /etc/dracut.conf.d 12 /etc/default 12 /etc/prelink.conf.d 12 /etc/modprobe.d 4 /etc/rsyslog.d 0 /etc/binfmt.d 0 /etc/modules-load.d 4 /etc/systemd/system/multi-user.target.wants 0 /etc/systemd/system/getty.target.wants 0 /etc/systemd/system/default.target.wants 0 /etc/systemd/system/system-update.target.wants 0 /etc/systemd/system/sysinit.target.wants 0 /etc/systemd/system/basic.target.wants 0 /etc/systemd/system/local-fs.target.wants 0 /etc/systemd/system/sockets.target.wants 4 /etc/systemd/system/redis-sentinel.service.d 4 /etc/systemd/system/redis.service.d 16 /etc/systemd/system 0 /etc/systemd/user 40 /etc/systemd 92 /etc/dbus-1/system.d 0 /etc/dbus-1/session.d 100 /etc/dbus-1 0 /etc/sysctl.d 0 /etc/tmpfiles.d 0 /etc/udev/rules.d 7764 /etc/udev 4 /etc/lvm/archive 4 /etc/lvm/backup 0 /etc/lvm/cache 28 /etc/lvm/profile 136 /etc/lvm 0 /etc/NetworkManager/dispatcher.d/no-wait.d 0 /etc/NetworkManager/dispatcher.d/pre-down.d 0 /etc/NetworkManager/dispatcher.d/pre-up.d 8 /etc/NetworkManager/dispatcher.d 0 /etc/NetworkManager/conf.d 0 /etc/NetworkManager/dnsmasq-shared.d 0 /etc/NetworkManager/dnsmasq.d 0 /etc/NetworkManager/system-connections 12 /etc/NetworkManager 72 /etc/profile.d 8 /etc/polkit-1/rules.d 0 /etc/polkit-1/localauthority/10-vendor.d 0 /etc/polkit-1/localauthority/20-org.d 0 /etc/polkit-1/localauthority/30-site.d 0 /etc/polkit-1/localauthority/50-local.d 0 /etc/polkit-1/localauthority/90-mandatory.d 0 /etc/polkit-1/localauthority 0 /etc/polkit-1/localauthority.conf.d 8 /etc/polkit-1 0 /etc/ppp/peers 28 /etc/ppp 8 /etc/ntp 0 /etc/X11/applnk 0 /etc/X11/fontpath.d 4 /etc/X11/xorg.conf.d 4 /etc/X11 20 /etc/bash_completion.d 0 /etc/opt 156 /etc/pki/ca-trust/extracted/java 256 /etc/pki/ca-trust/extracted/openssl 388 /etc/pki/ca-trust/extracted/pem 804 /etc/pki/ca-trust/extracted 0 /etc/pki/ca-trust/source/anchors 0 /etc/pki/ca-trust/source/blacklist 4 /etc/pki/ca-trust/source 816 /etc/pki/ca-trust 0 /etc/pki/java 12 /etc/pki/tls/certs 24 /etc/pki/tls/misc 0 /etc/pki/tls/private 48 /etc/pki/tls 16 /etc/pki/rpm-gpg 4 /etc/pki/nss-legacy 124 /etc/pki/nssdb 0 /etc/pki/CA/certs 0 /etc/pki/CA/crl 0 /etc/pki/CA/newcerts 0 /etc/pki/CA/private 0 /etc/pki/CA 0 /etc/pki/rsyslog 1008 /etc/pki 0 /etc/pm/config.d 0 /etc/pm/power.d 0 /etc/pm/sleep.d 0 /etc/pm 8 /etc/sysconfig/cbq 0 /etc/sysconfig/console 0 /etc/sysconfig/modules 256 /etc/sysconfig/network-scripts 352 /etc/sysconfig 0 /etc/xdg/autostart 0 /etc/xdg/systemd 0 /etc/xdg 0 /etc/xinetd.d 8 /etc/ld.so.conf.d 4 /etc/dhcp/dhclient-exit-hooks.d 0 /etc/dhcp/dhclient.d 4 /etc/dhcp 0 /etc/popt.d 0 /etc/statetab.d 0 /etc/pkcs11/modules 0 /etc/pkcs11 0 /etc/ssl 12 /etc/rpm 44 /etc/yum.repos.d 8 /etc/yum/vars 4 /etc/yum/protected.d 8 /etc/yum/pluginconf.d 0 /etc/yum/fssnap.d 24 /etc/yum 4 /etc/wpa_supplicant 4 /etc/cron.hourly 0 /etc/krb5.conf.d 0 /etc/gcrypt 0 /etc/cron.weekly 0 /etc/gss/mech.d 0 /etc/gss 0 /etc/security/console.apps 0 /etc/security/console.perms.d 8 /etc/security/limits.d 0 /etc/security/namespace.d 68 /etc/security 4 /etc/sasl2 0 /etc/groff/site-font 8 /etc/groff/site-tmac 8 /etc/groff 4 /etc/python 36 /etc/iproute2 12 /etc/my.cnf.d 64 /etc/openldap/certs 68 /etc/openldap 8 /etc/cron.daily 4 /etc/rwtab.d 24 /etc/logrotate.d 4 /etc/cron.d 0 /etc/cron.monthly 604 /etc/ssh 0 /etc/selinux/tmp 0 /etc/selinux/targeted/modules/active/modules 4 /etc/selinux/targeted/modules/active 4 /etc/selinux/targeted/modules 1848 /etc/selinux/targeted/contexts/files 28 /etc/selinux/targeted/contexts/users 1944 /etc/selinux/targeted/contexts 0 /etc/selinux/targeted/logins 3844 /etc/selinux/targeted/policy 32 /etc/selinux/targeted/active/modules/100/abrt 20 /etc/selinux/targeted/active/modules/100/accountsd 20 /etc/selinux/targeted/active/modules/100/acct 20 /etc/selinux/targeted/active/modules/100/afs 20 /etc/selinux/targeted/active/modules/100/aiccu 20 /etc/selinux/targeted/active/modules/100/aide 20 /etc/selinux/targeted/active/modules/100/ajaxterm 20 /etc/selinux/targeted/active/modules/100/alsa 20 /etc/selinux/targeted/active/modules/100/amanda 20 /etc/selinux/targeted/active/modules/100/amtu 28 /etc/selinux/targeted/active/modules/100/anaconda 24 /etc/selinux/targeted/active/modules/100/antivirus 48 /etc/selinux/targeted/active/modules/100/apache 20 /etc/selinux/targeted/active/modules/100/apcupsd 28 /etc/selinux/targeted/active/modules/100/apm 20 /etc/selinux/targeted/active/modules/100/application 20 /etc/selinux/targeted/active/modules/100/arpwatch 20 /etc/selinux/targeted/active/modules/100/asterisk 28 /etc/selinux/targeted/active/modules/100/auditadm 20 /etc/selinux/targeted/active/modules/100/authconfig 32 /etc/selinux/targeted/active/modules/100/authlogin 20 /etc/selinux/targeted/active/modules/100/automount 20 /etc/selinux/targeted/active/modules/100/avahi 20 /etc/selinux/targeted/active/modules/100/awstats 28 /etc/selinux/targeted/active/modules/100/bacula 120 /etc/selinux/targeted/active/modules/100/base 20 /etc/selinux/targeted/active/modules/100/bcfg2 28 /etc/selinux/targeted/active/modules/100/bind 20 /etc/selinux/targeted/active/modules/100/bitlbee 20 /etc/selinux/targeted/active/modules/100/blkmapd 20 /etc/selinux/targeted/active/modules/100/blueman 28 /etc/selinux/targeted/active/modules/100/bluetooth 28 /etc/selinux/targeted/active/modules/100/boinc 28 /etc/selinux/targeted/active/modules/100/bootloader 20 /etc/selinux/targeted/active/modules/100/brctl 20 /etc/selinux/targeted/active/modules/100/brltty 20 /etc/selinux/targeted/active/modules/100/bugzilla 20 /etc/selinux/targeted/active/modules/100/bumblebee 20 /etc/selinux/targeted/active/modules/100/cachefilesd 20 /etc/selinux/targeted/active/modules/100/calamaris 20 /etc/selinux/targeted/active/modules/100/callweaver 20 /etc/selinux/targeted/active/modules/100/canna 20 /etc/selinux/targeted/active/modules/100/ccs 20 /etc/selinux/targeted/active/modules/100/cdrecord 20 /etc/selinux/targeted/active/modules/100/certmaster 28 /etc/selinux/targeted/active/modules/100/certmonger 20 /etc/selinux/targeted/active/modules/100/certwatch 20 /etc/selinux/targeted/active/modules/100/cfengine 20 /etc/selinux/targeted/active/modules/100/cgdcbxd 20 /etc/selinux/targeted/active/modules/100/cgroup 28 /etc/selinux/targeted/active/modules/100/chrome 20 /etc/selinux/targeted/active/modules/100/chronyd 28 /etc/selinux/targeted/active/modules/100/cinder 20 /etc/selinux/targeted/active/modules/100/cipe 20 /etc/selinux/targeted/active/modules/100/clock 20 /etc/selinux/targeted/active/modules/100/clogd 28 /etc/selinux/targeted/active/modules/100/cloudform 20 /etc/selinux/targeted/active/modules/100/cmirrord 20 /etc/selinux/targeted/active/modules/100/cobbler 20 /etc/selinux/targeted/active/modules/100/cockpit 20 /etc/selinux/targeted/active/modules/100/collectd 20 /etc/selinux/targeted/active/modules/100/colord 20 /etc/selinux/targeted/active/modules/100/comsat 28 /etc/selinux/targeted/active/modules/100/condor 20 /etc/selinux/targeted/active/modules/100/conman 28 /etc/selinux/targeted/active/modules/100/consolekit 28 /etc/selinux/targeted/active/modules/100/container 20 /etc/selinux/targeted/active/modules/100/couchdb 20 /etc/selinux/targeted/active/modules/100/courier 20 /etc/selinux/targeted/active/modules/100/cpucontrol 20 /etc/selinux/targeted/active/modules/100/cpufreqselector 20 /etc/selinux/targeted/active/modules/100/cpuplug 36 /etc/selinux/targeted/active/modules/100/cron 20 /etc/selinux/targeted/active/modules/100/ctdb 32 /etc/selinux/targeted/active/modules/100/cups 20 /etc/selinux/targeted/active/modules/100/cvs 20 /etc/selinux/targeted/active/modules/100/cyphesis 20 /etc/selinux/targeted/active/modules/100/cyrus 20 /etc/selinux/targeted/active/modules/100/daemontools 24 /etc/selinux/targeted/active/modules/100/dbadm 20 /etc/selinux/targeted/active/modules/100/dbskk 28 /etc/selinux/targeted/active/modules/100/dbus 20 /etc/selinux/targeted/active/modules/100/dcc 20 /etc/selinux/targeted/active/modules/100/ddclient 20 /etc/selinux/targeted/active/modules/100/denyhosts 32 /etc/selinux/targeted/active/modules/100/devicekit 20 /etc/selinux/targeted/active/modules/100/dhcp 20 /etc/selinux/targeted/active/modules/100/dictd 28 /etc/selinux/targeted/active/modules/100/dirsrv 28 /etc/selinux/targeted/active/modules/100/dirsrv-admin 20 /etc/selinux/targeted/active/modules/100/dmesg 20 /etc/selinux/targeted/active/modules/100/dmidecode 20 /etc/selinux/targeted/active/modules/100/dnsmasq 20 /etc/selinux/targeted/active/modules/100/dnssec 28 /etc/selinux/targeted/active/modules/100/dovecot 20 /etc/selinux/targeted/active/modules/100/drbd 20 /etc/selinux/targeted/active/modules/100/dspam 20 /etc/selinux/targeted/active/modules/100/entropyd 24 /etc/selinux/targeted/active/modules/100/exim 20 /etc/selinux/targeted/active/modules/100/fail2ban 20 /etc/selinux/targeted/active/modules/100/fcoe 20 /etc/selinux/targeted/active/modules/100/fetchmail 20 /etc/selinux/targeted/active/modules/100/finger 20 /etc/selinux/targeted/active/modules/100/firewalld 20 /etc/selinux/targeted/active/modules/100/firewallgui 20 /etc/selinux/targeted/active/modules/100/firstboot 20 /etc/selinux/targeted/active/modules/100/fprintd 20 /etc/selinux/targeted/active/modules/100/freeipmi 20 /etc/selinux/targeted/active/modules/100/freqset 28 /etc/selinux/targeted/active/modules/100/fstools 28 /etc/selinux/targeted/active/modules/100/ftp 28 /etc/selinux/targeted/active/modules/100/games 20 /etc/selinux/targeted/active/modules/100/gdomap 20 /etc/selinux/targeted/active/modules/100/geoclue 20 /etc/selinux/targeted/active/modules/100/getty 20 /etc/selinux/targeted/active/modules/100/git 20 /etc/selinux/targeted/active/modules/100/gitosis 20 /etc/selinux/targeted/active/modules/100/glance 28 /etc/selinux/targeted/active/modules/100/glusterd 20 /etc/selinux/targeted/active/modules/100/gnome 28 /etc/selinux/targeted/active/modules/100/gpg 20 /etc/selinux/targeted/active/modules/100/gpm 20 /etc/selinux/targeted/active/modules/100/gpsd 20 /etc/selinux/targeted/active/modules/100/gssproxy 28 /etc/selinux/targeted/active/modules/100/guest 20 /etc/selinux/targeted/active/modules/100/hddtemp 20 /etc/selinux/targeted/active/modules/100/hostname 20 /etc/selinux/targeted/active/modules/100/hsqldb 20 /etc/selinux/targeted/active/modules/100/hwloc 20 /etc/selinux/targeted/active/modules/100/hypervkvp 20 /etc/selinux/targeted/active/modules/100/icecast 28 /etc/selinux/targeted/active/modules/100/inetd 56 /etc/selinux/targeted/active/modules/100/init 20 /etc/selinux/targeted/active/modules/100/inn 20 /etc/selinux/targeted/active/modules/100/iodine 20 /etc/selinux/targeted/active/modules/100/iotop 20 /etc/selinux/targeted/active/modules/100/ipa 20 /etc/selinux/targeted/active/modules/100/ipmievd 28 /etc/selinux/targeted/active/modules/100/ipsec 24 /etc/selinux/targeted/active/modules/100/iptables 20 /etc/selinux/targeted/active/modules/100/irc 20 /etc/selinux/targeted/active/modules/100/irqbalance 20 /etc/selinux/targeted/active/modules/100/iscsi 20 /etc/selinux/targeted/active/modules/100/isns 20 /etc/selinux/targeted/active/modules/100/jabber 16 /etc/selinux/targeted/active/modules/100/jetty 20 /etc/selinux/targeted/active/modules/100/jockey 20 /etc/selinux/targeted/active/modules/100/journalctl 28 /etc/selinux/targeted/active/modules/100/kdump 20 /etc/selinux/targeted/active/modules/100/kdumpgui 20 /etc/selinux/targeted/active/modules/100/keepalived 28 /etc/selinux/targeted/active/modules/100/kerberos 16 /etc/selinux/targeted/active/modules/100/keyboardd 24 /etc/selinux/targeted/active/modules/100/keystone 20 /etc/selinux/targeted/active/modules/100/kismet 20 /etc/selinux/targeted/active/modules/100/kmscon 20 /etc/selinux/targeted/active/modules/100/ksmtuned 20 /etc/selinux/targeted/active/modules/100/ktalk 20 /etc/selinux/targeted/active/modules/100/l2tp 20 /etc/selinux/targeted/active/modules/100/ldap 28 /etc/selinux/targeted/active/modules/100/libraries 28 /etc/selinux/targeted/active/modules/100/likewise 20 /etc/selinux/targeted/active/modules/100/linuxptp 20 /etc/selinux/targeted/active/modules/100/lircd 20 /etc/selinux/targeted/active/modules/100/livecd 20 /etc/selinux/targeted/active/modules/100/lldpad 20 /etc/selinux/targeted/active/modules/100/loadkeys 28 /etc/selinux/targeted/active/modules/100/locallogin 20 /etc/selinux/targeted/active/modules/100/lockdev 20 /etc/selinux/targeted/active/modules/100/logadm 28 /etc/selinux/targeted/active/modules/100/logging 28 /etc/selinux/targeted/active/modules/100/logrotate 20 /etc/selinux/targeted/active/modules/100/logwatch 20 /etc/selinux/targeted/active/modules/100/lpd 20 /etc/selinux/targeted/active/modules/100/lsm 20 /etc/selinux/targeted/active/modules/100/lttng-tools 28 /etc/selinux/targeted/active/modules/100/lvm 20 /etc/selinux/targeted/active/modules/100/mailman 20 /etc/selinux/targeted/active/modules/100/mailscanner 20 /etc/selinux/targeted/active/modules/100/man2html 20 /etc/selinux/targeted/active/modules/100/mandb 20 /etc/selinux/targeted/active/modules/100/mcelog 20 /etc/selinux/targeted/active/modules/100/mediawiki 20 /etc/selinux/targeted/active/modules/100/memcached 20 /etc/selinux/targeted/active/modules/100/milter 20 /etc/selinux/targeted/active/modules/100/minidlna 20 /etc/selinux/targeted/active/modules/100/minissdpd 20 /etc/selinux/targeted/active/modules/100/mip6d 20 /etc/selinux/targeted/active/modules/100/mirrormanager 20 /etc/selinux/targeted/active/modules/100/miscfiles 20 /etc/selinux/targeted/active/modules/100/mock 20 /etc/selinux/targeted/active/modules/100/modemmanager 28 /etc/selinux/targeted/active/modules/100/modutils 20 /etc/selinux/targeted/active/modules/100/mojomojo 20 /etc/selinux/targeted/active/modules/100/mon_statd 20 /etc/selinux/targeted/active/modules/100/mongodb 20 /etc/selinux/targeted/active/modules/100/motion 28 /etc/selinux/targeted/active/modules/100/mount 36 /etc/selinux/targeted/active/modules/100/mozilla 20 /etc/selinux/targeted/active/modules/100/mpd 20 /etc/selinux/targeted/active/modules/100/mplayer 20 /etc/selinux/targeted/active/modules/100/mrtg 28 /etc/selinux/targeted/active/modules/100/mta 32 /etc/selinux/targeted/active/modules/100/munin 28 /etc/selinux/targeted/active/modules/100/mysql 20 /etc/selinux/targeted/active/modules/100/mythtv 36 /etc/selinux/targeted/active/modules/100/nagios 20 /etc/selinux/targeted/active/modules/100/namespace 20 /etc/selinux/targeted/active/modules/100/ncftool 20 /etc/selinux/targeted/active/modules/100/netlabel 20 /etc/selinux/targeted/active/modules/100/netutils 28 /etc/selinux/targeted/active/modules/100/networkmanager 20 /etc/selinux/targeted/active/modules/100/ninfod 20 /etc/selinux/targeted/active/modules/100/nis 20 /etc/selinux/targeted/active/modules/100/nova 20 /etc/selinux/targeted/active/modules/100/nscd 20 /etc/selinux/targeted/active/modules/100/nsd 20 /etc/selinux/targeted/active/modules/100/nslcd 20 /etc/selinux/targeted/active/modules/100/ntop 20 /etc/selinux/targeted/active/modules/100/ntp 20 /etc/selinux/targeted/active/modules/100/numad 20 /etc/selinux/targeted/active/modules/100/nut 20 /etc/selinux/targeted/active/modules/100/nx 20 /etc/selinux/targeted/active/modules/100/obex 20 /etc/selinux/targeted/active/modules/100/oddjob 20 /etc/selinux/targeted/active/modules/100/openct 20 /etc/selinux/targeted/active/modules/100/opendnssec 20 /etc/selinux/targeted/active/modules/100/openhpid 32 /etc/selinux/targeted/active/modules/100/openshift 16 /etc/selinux/targeted/active/modules/100/openshift-origin 20 /etc/selinux/targeted/active/modules/100/opensm 28 /etc/selinux/targeted/active/modules/100/openvpn 20 /etc/selinux/targeted/active/modules/100/openvswitch 20 /etc/selinux/targeted/active/modules/100/openwsman 20 /etc/selinux/targeted/active/modules/100/oracleasm 20 /etc/selinux/targeted/active/modules/100/osad 20 /etc/selinux/targeted/active/modules/100/pads 20 /etc/selinux/targeted/active/modules/100/passenger 20 /etc/selinux/targeted/active/modules/100/pcmcia 28 /etc/selinux/targeted/active/modules/100/pcp 20 /etc/selinux/targeted/active/modules/100/pcscd 36 /etc/selinux/targeted/active/modules/100/pegasus 8 /etc/selinux/targeted/active/modules/100/permissivedomains 20 /etc/selinux/targeted/active/modules/100/pesign 20 /etc/selinux/targeted/active/modules/100/pingd 28 /etc/selinux/targeted/active/modules/100/piranha 20 /etc/selinux/targeted/active/modules/100/pkcs 28 /etc/selinux/targeted/active/modules/100/pki 20 /etc/selinux/targeted/active/modules/100/plymouthd 20 /etc/selinux/targeted/active/modules/100/podsleuth 28 /etc/selinux/targeted/active/modules/100/policykit 20 /etc/selinux/targeted/active/modules/100/polipo 20 /etc/selinux/targeted/active/modules/100/portmap 20 /etc/selinux/targeted/active/modules/100/portreserve 32 /etc/selinux/targeted/active/modules/100/postfix 28 /etc/selinux/targeted/active/modules/100/postgresql 20 /etc/selinux/targeted/active/modules/100/postgrey 28 /etc/selinux/targeted/active/modules/100/ppp 28 /etc/selinux/targeted/active/modules/100/prelink 28 /etc/selinux/targeted/active/modules/100/prelude 20 /etc/selinux/targeted/active/modules/100/privoxy 20 /etc/selinux/targeted/active/modules/100/procmail 20 /etc/selinux/targeted/active/modules/100/prosody 20 /etc/selinux/targeted/active/modules/100/psad 20 /etc/selinux/targeted/active/modules/100/ptchown 20 /etc/selinux/targeted/active/modules/100/publicfile 28 /etc/selinux/targeted/active/modules/100/pulseaudio 28 /etc/selinux/targeted/active/modules/100/puppet 20 /etc/selinux/targeted/active/modules/100/pwauth 20 /etc/selinux/targeted/active/modules/100/qmail 20 /etc/selinux/targeted/active/modules/100/qpid 28 /etc/selinux/targeted/active/modules/100/quantum 20 /etc/selinux/targeted/active/modules/100/quota 20 /etc/selinux/targeted/active/modules/100/rabbitmq 20 /etc/selinux/targeted/active/modules/100/radius 20 /etc/selinux/targeted/active/modules/100/radvd 20 /etc/selinux/targeted/active/modules/100/raid 20 /etc/selinux/targeted/active/modules/100/rasdaemon 20 /etc/selinux/targeted/active/modules/100/rdisc 20 /etc/selinux/targeted/active/modules/100/readahead 32 /etc/selinux/targeted/active/modules/100/realmd 20 /etc/selinux/targeted/active/modules/100/redis 20 /etc/selinux/targeted/active/modules/100/remotelogin 36 /etc/selinux/targeted/active/modules/100/rhcs 28 /etc/selinux/targeted/active/modules/100/rhev 20 /etc/selinux/targeted/active/modules/100/rhgb 20 /etc/selinux/targeted/active/modules/100/rhnsd 20 /etc/selinux/targeted/active/modules/100/rhsmcertd 28 /etc/selinux/targeted/active/modules/100/ricci 16 /etc/selinux/targeted/active/modules/100/rkhunter 24 /etc/selinux/targeted/active/modules/100/rlogin 20 /etc/selinux/targeted/active/modules/100/rngd 20 /etc/selinux/targeted/active/modules/100/roundup 28 /etc/selinux/targeted/active/modules/100/rpc 20 /etc/selinux/targeted/active/modules/100/rpcbind 36 /etc/selinux/targeted/active/modules/100/rpm 20 /etc/selinux/targeted/active/modules/100/rshd 20 /etc/selinux/targeted/active/modules/100/rssh 20 /etc/selinux/targeted/active/modules/100/rsync 20 /etc/selinux/targeted/active/modules/100/rtas 20 /etc/selinux/targeted/active/modules/100/rtkit 20 /etc/selinux/targeted/active/modules/100/rwho 44 /etc/selinux/targeted/active/modules/100/samba 20 /etc/selinux/targeted/active/modules/100/sambagui 28 /etc/selinux/targeted/active/modules/100/sandboxX 20 /etc/selinux/targeted/active/modules/100/sanlock 20 /etc/selinux/targeted/active/modules/100/sasl 20 /etc/selinux/targeted/active/modules/100/sbd 20 /etc/selinux/targeted/active/modules/100/sblim 20 /etc/selinux/targeted/active/modules/100/screen 28 /etc/selinux/targeted/active/modules/100/secadm 20 /etc/selinux/targeted/active/modules/100/sectoolm 36 /etc/selinux/targeted/active/modules/100/selinuxutil 28 /etc/selinux/targeted/active/modules/100/sendmail 20 /etc/selinux/targeted/active/modules/100/sensord 20 /etc/selinux/targeted/active/modules/100/setrans 20 /etc/selinux/targeted/active/modules/100/setroubleshoot 20 /etc/selinux/targeted/active/modules/100/seunshare 28 /etc/selinux/targeted/active/modules/100/sge 20 /etc/selinux/targeted/active/modules/100/shorewall 20 /etc/selinux/targeted/active/modules/100/slocate 20 /etc/selinux/targeted/active/modules/100/slpd 20 /etc/selinux/targeted/active/modules/100/smartmon 20 /etc/selinux/targeted/active/modules/100/smokeping 20 /etc/selinux/targeted/active/modules/100/smoltclient 20 /etc/selinux/targeted/active/modules/100/smsd 20 /etc/selinux/targeted/active/modules/100/snapper 20 /etc/selinux/targeted/active/modules/100/snmp 20 /etc/selinux/targeted/active/modules/100/snort 28 /etc/selinux/targeted/active/modules/100/sosreport 20 /etc/selinux/targeted/active/modules/100/soundserver 28 /etc/selinux/targeted/active/modules/100/spamassassin 20 /etc/selinux/targeted/active/modules/100/speech-dispatcher 28 /etc/selinux/targeted/active/modules/100/squid 36 /etc/selinux/targeted/active/modules/100/ssh 24 /etc/selinux/targeted/active/modules/100/sssd 68 /etc/selinux/targeted/active/modules/100/staff 20 /etc/selinux/targeted/active/modules/100/stapserver 20 /etc/selinux/targeted/active/modules/100/stunnel 20 /etc/selinux/targeted/active/modules/100/su 20 /etc/selinux/targeted/active/modules/100/sudo 20 /etc/selinux/targeted/active/modules/100/svnserve 20 /etc/selinux/targeted/active/modules/100/swift 92 /etc/selinux/targeted/active/modules/100/sysadm 20 /etc/selinux/targeted/active/modules/100/sysadm_secadm 28 /etc/selinux/targeted/active/modules/100/sysnetwork 20 /etc/selinux/targeted/active/modules/100/sysstat 36 /etc/selinux/targeted/active/modules/100/systemd 20 /etc/selinux/targeted/active/modules/100/tangd 20 /etc/selinux/targeted/active/modules/100/targetd 20 /etc/selinux/targeted/active/modules/100/tcpd 20 /etc/selinux/targeted/active/modules/100/tcsd 24 /etc/selinux/targeted/active/modules/100/telepathy 20 /etc/selinux/targeted/active/modules/100/telnet 20 /etc/selinux/targeted/active/modules/100/tftp 20 /etc/selinux/targeted/active/modules/100/tgtd 20 /etc/selinux/targeted/active/modules/100/thin 20 /etc/selinux/targeted/active/modules/100/thumb 20 /etc/selinux/targeted/active/modules/100/tlp 20 /etc/selinux/targeted/active/modules/100/tor 20 /etc/selinux/targeted/active/modules/100/tmpreaper 20 /etc/selinux/targeted/active/modules/100/tomcat 20 /etc/selinux/targeted/active/modules/100/tuned 20 /etc/selinux/targeted/active/modules/100/tvtime 36 /etc/selinux/targeted/active/modules/100/udev 20 /etc/selinux/targeted/active/modules/100/ulogd 20 /etc/selinux/targeted/active/modules/100/uml 20 /etc/selinux/targeted/active/modules/100/unconfined 36 /etc/selinux/targeted/active/modules/100/unconfineduser 16 /etc/selinux/targeted/active/modules/100/unlabelednet 60 /etc/selinux/targeted/active/modules/100/unprivuser 20 /etc/selinux/targeted/active/modules/100/updfstab 20 /etc/selinux/targeted/active/modules/100/usbmodules 20 /etc/selinux/targeted/active/modules/100/usbmuxd 28 /etc/selinux/targeted/active/modules/100/userdomain 20 /etc/selinux/targeted/active/modules/100/userhelper 32 /etc/selinux/targeted/active/modules/100/usermanage 20 /etc/selinux/targeted/active/modules/100/usernetctl 20 /etc/selinux/targeted/active/modules/100/uucp 20 /etc/selinux/targeted/active/modules/100/uuidd 20 /etc/selinux/targeted/active/modules/100/varnishd 20 /etc/selinux/targeted/active/modules/100/vdagent 20 /etc/selinux/targeted/active/modules/100/vhostmd 56 /etc/selinux/targeted/active/modules/100/virt 20 /etc/selinux/targeted/active/modules/100/vlock 28 /etc/selinux/targeted/active/modules/100/vmtools 28 /etc/selinux/targeted/active/modules/100/vmware 20 /etc/selinux/targeted/active/modules/100/vnstatd 20 /etc/selinux/targeted/active/modules/100/vpn 20 /etc/selinux/targeted/active/modules/100/w3c 28 /etc/selinux/targeted/active/modules/100/watchdog 20 /etc/selinux/targeted/active/modules/100/wdmd 24 /etc/selinux/targeted/active/modules/100/webadm 20 /etc/selinux/targeted/active/modules/100/webalizer 20 /etc/selinux/targeted/active/modules/100/wine 20 /etc/selinux/targeted/active/modules/100/wireshark 28 /etc/selinux/targeted/active/modules/100/xen 40 /etc/selinux/targeted/active/modules/100/xguest 56 /etc/selinux/targeted/active/modules/100/xserver 28 /etc/selinux/targeted/active/modules/100/zabbix 20 /etc/selinux/targeted/active/modules/100/zarafa 20 /etc/selinux/targeted/active/modules/100/zebra 20 /etc/selinux/targeted/active/modules/100/zoneminder 20 /etc/selinux/targeted/active/modules/100/zosremote 9376 /etc/selinux/targeted/active/modules/100 0 /etc/selinux/targeted/active/modules/disabled 40 /etc/selinux/targeted/active/modules/200/container 40 /etc/selinux/targeted/active/modules/200 9416 /etc/selinux/targeted/active/modules 17532 /etc/selinux/targeted/active 23340 /etc/selinux/targeted 0 /etc/selinux/final 23348 /etc/selinux 4 /etc/plymouth 0 /etc/gnupg 0 /etc/tuned/recommend.d 16 /etc/tuned 0 /etc/firewalld/helpers 0 /etc/firewalld/icmptypes 0 /etc/firewalld/ipsets 0 /etc/firewalld/services 8 /etc/firewalld/zones 16 /etc/firewalld 8 /etc/audisp/plugins.d 12 /etc/audisp 4 /etc/audit/rules.d 16 /etc/audit 148 /etc/postfix 4 /etc/kernel/postinst.d 4 /etc/kernel 0 /etc/sudoers.d 4 /etc/containerd 8 /etc/docker 35492 /etc/ [root@yinzhengjie.com ~]#
4>:.指定查看目录的深度
[root@yinzhengjie.com ~]# du /etc/ --max-depth=1 72 /etc/grub.d 0 /etc/terminfo 12 /etc/skel 0 /etc/alternatives 0 /etc/chkconfig.d 8 /etc/libnl 44 /etc/rc.d 100 /etc/pam.d 4 /etc/depmod.d 0 /etc/dracut.conf.d 12 /etc/default 12 /etc/prelink.conf.d 12 /etc/modprobe.d 4 /etc/rsyslog.d 0 /etc/binfmt.d 0 /etc/modules-load.d 40 /etc/systemd 100 /etc/dbus-1 0 /etc/sysctl.d 0 /etc/tmpfiles.d 7764 /etc/udev 136 /etc/lvm 12 /etc/NetworkManager 72 /etc/profile.d 8 /etc/polkit-1 28 /etc/ppp 8 /etc/ntp 4 /etc/X11 20 /etc/bash_completion.d 0 /etc/opt 1008 /etc/pki 0 /etc/pm 352 /etc/sysconfig 0 /etc/xdg 0 /etc/xinetd.d 8 /etc/ld.so.conf.d 4 /etc/dhcp 0 /etc/popt.d 0 /etc/statetab.d 0 /etc/pkcs11 0 /etc/ssl 12 /etc/rpm 44 /etc/yum.repos.d 24 /etc/yum 4 /etc/wpa_supplicant 4 /etc/cron.hourly 0 /etc/krb5.conf.d 0 /etc/gcrypt 0 /etc/cron.weekly 0 /etc/gss 68 /etc/security 4 /etc/sasl2 8 /etc/groff 4 /etc/python 36 /etc/iproute2 12 /etc/my.cnf.d 68 /etc/openldap 8 /etc/cron.daily 4 /etc/rwtab.d 24 /etc/logrotate.d 4 /etc/cron.d 0 /etc/cron.monthly 604 /etc/ssh 23348 /etc/selinux 4 /etc/plymouth 0 /etc/gnupg 16 /etc/tuned 16 /etc/firewalld 12 /etc/audisp 16 /etc/audit 148 /etc/postfix 4 /etc/kernel 0 /etc/sudoers.d 4 /etc/containerd 8 /etc/docker 35492 /etc/ [root@yinzhengjie.com ~]#
5>.以人性化的形式显示
[root@yinzhengjie.com ~]# du -sh /* 0 /bin 100M /boot 0 /dev 35M /etc 16K /home 0 /lib 0 /lib64 0 /media 1.8G /mnt 16K /opt du: cannot access ‘/proc/6403/task/6403/fd/4’: No such file or directory du: cannot access ‘/proc/6403/task/6403/fdinfo/4’: No such file or directory du: cannot access ‘/proc/6403/fd/4’: No such file or directory du: cannot access ‘/proc/6403/fdinfo/4’: No such file or directory 0 /proc 60K /root 12M /run 0 /sbin 0 /srv 0 /sys 0 /tmp 1.6G /usr 1.8G /var 1.4G /yinzhengjie [root@yinzhengjie.com ~]#
三.转换和复制文件(convert and copy a file)工具-dd
1>.查看dd命令的帮助信息
[root@yinzhengjie.com ~]# dd --help Usage: dd [OPERAND]... or: dd OPTION Copy a file, converting and formatting according to the operands. bs=BYTES read and write up to BYTES bytes at a time cbs=BYTES convert BYTES bytes at a time conv=CONVS convert the file as per the comma separated symbol list count=N copy only N input blocks ibs=BYTES read up to BYTES bytes at a time (default: 512) if=FILE read from FILE instead of stdin iflag=FLAGS read as per the comma separated symbol list obs=BYTES write BYTES bytes at a time (default: 512) of=FILE write to FILE instead of stdout oflag=FLAGS write as per the comma separated symbol list seek=N skip N obs-sized blocks at start of output skip=N skip N ibs-sized blocks at start of input status=LEVEL The LEVEL of information to print to stderr; 'none' suppresses everything but error messages, 'noxfer' suppresses the final transfer statistics, 'progress' shows periodic transfer statistics N and BYTES may be followed by the following multiplicative suffixes: c =1, w =2, b =512, kB =1000, K =1024, MB =1000*1000, M =1024*1024, xM =M GB =1000*1000*1000, G =1024*1024*1024, and so on for T, P, E, Z, Y. Each CONV symbol may be: ascii from EBCDIC to ASCII ebcdic from ASCII to EBCDIC ibm from ASCII to alternate EBCDIC block pad newline-terminated records with spaces to cbs-size unblock replace trailing spaces in cbs-size records with newline lcase change upper case to lower case ucase change lower case to upper case sparse try to seek rather than write the output for NUL input blocks swab swap every pair of input bytes sync pad every input block with NULs to ibs-size; when used with block or unblock, pad with spaces rather than NULs excl fail if the output file already exists nocreat do not create the output file notrunc do not truncate the output file noerror continue after read errors fdatasync physically write output file data before finishing fsync likewise, but also write metadata Each FLAG symbol may be: append append mode (makes sense only for output; conv=notrunc suggested) direct use direct I/O for data directory fail unless a directory dsync use synchronized I/O for data sync likewise, but also for metadata fullblock accumulate full blocks of input (iflag only) nonblock use non-blocking I/O noatime do not update access time nocache discard cached data noctty do not assign controlling terminal from file nofollow do not follow symlinks count_bytes treat 'count=N' as a byte count (iflag only) skip_bytes treat 'skip=N' as a byte count (iflag only) seek_bytes treat 'seek=N' as a byte count (oflag only) Sending a USR1 signal to a running 'dd' process makes it print I/O statistics to standard error and then resume copying. $ dd if=/dev/zero of=/dev/null& pid=$! $ kill -USR1 $pid; sleep 1; kill $pid 18335302+0 records in 18335302+0 records out 9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s Options are: --help display this help and exit --version output version information and exit GNU coreutils online help: <http://www.gnu.org/software/coreutils/> For complete documentation, run: info coreutils 'dd invocation' [root@yinzhengjie.com ~]#
dd命令常用选项介绍: if: 指定源文件，即从所命名文件读取而不是从标准输入 of: 指定目标文件，即写到所命名的文件而不是到标准输出。 bs: 指定块大小（既是是ibs也是obs) ibs: 一次读size个byte obs: 一次写size个byte cbs: 一次转化size个byte skip: 从开头忽略blocks个ibs大小的块 seek: 从开头忽略blocks个obs大小的块 count: 只拷贝n个记录 conv: 用指定的参数转换文件,常见的转换参数如下所示: ascii: 转换EBCDIC 为ASCII ebcdic: 转换ASCII 为EBCDIC lcase: 把大写字符转换为小写字符 ucase: 把小写字符转换为大写字符 nocreat: 不创建输出文件 noerror: 出错时不停止 notrunc: 不截断输出文件 sync: 把每个输入块填充到ibs个字节，不足部分用空(NUL)字符补齐 Fdatasync: 写完成前，物理写入输出文件
2>.使用dd命令备份MBR
[root@yinzhengjie.com ~]# dd if=/dev/sda of=/tmp/mbr.bak bs=512 count=1 1+0 records in 1+0 records out 512 bytes (512 B) copied, 0.000135145 s, 3.8 MB/s [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# ll /tmp/mbr.bak -rw-r--r-- 1 root root 512 May 28 19:26 /tmp/mbr.bak [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# hexdump -C /tmp/mbr.bak 00000000 eb 63 90 00 00 00 00 00 00 00 00 00 00 00 00 00 |.c..............| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000050 00 00 00 00 00 00 00 00 00 00 00 80 00 08 00 00 |................| 00000060 00 00 00 00 ff fa 90 90 f6 c2 80 74 05 f6 c2 70 |...........t...p| 00000070 74 02 b2 80 ea 79 7c 00 00 31 c0 8e d8 8e d0 bc |t....y|..1......| 00000080 00 20 fb a0 64 7c 3c ff 74 02 88 c2 52 be 05 7c |. ..d|<.t...R..|| 00000090 b4 41 bb aa 55 cd 13 5a 52 72 3d 81 fb 55 aa 75 |.A..U..ZRr=..U.u| 000000a0 37 83 e1 01 74 32 31 c0 89 44 04 40 88 44 ff 89 |7...t21..D.@.D..| 000000b0 44 02 c7 04 10 00 66 8b 1e 5c 7c 66 89 5c 08 66 |D.....f..\|f.\.f| 000000c0 8b 1e 60 7c 66 89 5c 0c c7 44 06 00 70 b4 42 cd |..`|f.\..D..p.B.| 000000d0 13 72 05 bb 00 70 eb 76 b4 08 cd 13 73 0d 5a 84 |.r...p.v....s.Z.| 000000e0 d2 0f 83 de 00 be 85 7d e9 82 00 66 0f b6 c6 88 |.......}...f....| 000000f0 64 ff 40 66 89 44 04 0f b6 d1 c1 e2 02 88 e8 88 |d.@f.D..........| 00000100 f4 40 89 44 08 0f b6 c2 c0 e8 02 66 89 04 66 a1 |.@.D.......f..f.| 00000110 60 7c 66 09 c0 75 4e 66 a1 5c 7c 66 31 d2 66 f7 |`|f..uNf.\|f1.f.| 00000120 34 88 d1 31 d2 66 f7 74 04 3b 44 08 7d 37 fe c1 |4..1.f.t.;D.}7..| 00000130 88 c5 30 c0 c1 e8 02 08 c1 88 d0 5a 88 c6 bb 00 |..0........Z....| 00000140 70 8e c3 31 db b8 01 02 cd 13 72 1e 8c c3 60 1e |p..1......r...`.| 00000150 b9 00 01 8e db 31 f6 bf 00 80 8e c6 fc f3 a5 1f |.....1..........| 00000160 61 ff 26 5a 7c be 80 7d eb 03 be 8f 7d e8 34 00 |a.&Z|..}....}.4.| 00000170 be 94 7d e8 2e 00 cd 18 eb fe 47 52 55 42 20 00 |..}.......GRUB .| 00000180 47 65 6f 6d 00 48 61 72 64 20 44 69 73 6b 00 52 |Geom.Hard Disk.R| 00000190 65 61 64 00 20 45 72 72 6f 72 0d 0a 00 bb 01 00 |ead. Error......| 000001a0 b4 0e cd 10 ac 3c 00 75 f4 c3 00 00 00 00 00 00 |.....<.u........| 000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001c0 01 00 ee fe ff ff 01 00 00 00 ff ff ff ff 00 00 |................| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 [root@yinzhengjie.com ~]#
3>.破坏MBR中的bootloader
[root@yinzhengjie.com ~]# hexdump -C /dev/sda -n 512 00000000 eb 63 90 00 00 00 00 00 00 00 00 00 00 00 00 00 |.c..............| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000050 00 00 00 00 00 00 00 00 00 00 00 80 00 08 00 00 |................| 00000060 00 00 00 00 ff fa 90 90 f6 c2 80 74 05 f6 c2 70 |...........t...p| 00000070 74 02 b2 80 ea 79 7c 00 00 31 c0 8e d8 8e d0 bc |t....y|..1......| 00000080 00 20 fb a0 64 7c 3c ff 74 02 88 c2 52 be 05 7c |. ..d|<.t...R..|| 00000090 b4 41 bb aa 55 cd 13 5a 52 72 3d 81 fb 55 aa 75 |.A..U..ZRr=..U.u| 000000a0 37 83 e1 01 74 32 31 c0 89 44 04 40 88 44 ff 89 |7...t21..D.@.D..| 000000b0 44 02 c7 04 10 00 66 8b 1e 5c 7c 66 89 5c 08 66 |D.....f..\|f.\.f| 000000c0 8b 1e 60 7c 66 89 5c 0c c7 44 06 00 70 b4 42 cd |..`|f.\..D..p.B.| 000000d0 13 72 05 bb 00 70 eb 76 b4 08 cd 13 73 0d 5a 84 |.r...p.v....s.Z.| 000000e0 d2 0f 83 de 00 be 85 7d e9 82 00 66 0f b6 c6 88 |.......}...f....| 000000f0 64 ff 40 66 89 44 04 0f b6 d1 c1 e2 02 88 e8 88 |d.@f.D..........| 00000100 f4 40 89 44 08 0f b6 c2 c0 e8 02 66 89 04 66 a1 |.@.D.......f..f.| 00000110 60 7c 66 09 c0 75 4e 66 a1 5c 7c 66 31 d2 66 f7 |`|f..uNf.\|f1.f.| 00000120 34 88 d1 31 d2 66 f7 74 04 3b 44 08 7d 37 fe c1 |4..1.f.t.;D.}7..| 00000130 88 c5 30 c0 c1 e8 02 08 c1 88 d0 5a 88 c6 bb 00 |..0........Z....| 00000140 70 8e c3 31 db b8 01 02 cd 13 72 1e 8c c3 60 1e |p..1......r...`.| 00000150 b9 00 01 8e db 31 f6 bf 00 80 8e c6 fc f3 a5 1f |.....1..........| 00000160 61 ff 26 5a 7c be 80 7d eb 03 be 8f 7d e8 34 00 |a.&Z|..}....}.4.| 00000170 be 94 7d e8 2e 00 cd 18 eb fe 47 52 55 42 20 00 |..}.......GRUB .| 00000180 47 65 6f 6d 00 48 61 72 64 20 44 69 73 6b 00 52 |Geom.Hard Disk.R| 00000190 65 61 64 00 20 45 72 72 6f 72 0d 0a 00 bb 01 00 |ead. Error......| 000001a0 b4 0e cd 10 ac 3c 00 75 f4 c3 00 00 00 00 00 00 |.....<.u........| 000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001c0 01 00 ee fe ff ff 01 00 00 00 ff ff ff ff 00 00 |................| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# dd if=/dev/zero of=/dev/sda bs=64 count=1 seek=446 1+0 records in 1+0 records out 64 bytes (64 B) copied, 0.000603372 s, 106 kB/s [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# hexdump -C /dev/sda -n 512 -v 00000000 eb 63 90 00 00 00 00 00 00 00 00 00 00 00 00 00 |.c..............| 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00000050 00 00 00 00 00 00 00 00 00 00 00 80 00 08 00 00 |................| 00000060 00 00 00 00 ff fa 90 90 f6 c2 80 74 05 f6 c2 70 |...........t...p| 00000070 74 02 b2 80 ea 79 7c 00 00 31 c0 8e d8 8e d0 bc |t....y|..1......| 00000080 00 20 fb a0 64 7c 3c ff 74 02 88 c2 52 be 05 7c |. ..d|<.t...R..|| 00000090 b4 41 bb aa 55 cd 13 5a 52 72 3d 81 fb 55 aa 75 |.A..U..ZRr=..U.u| 000000a0 37 83 e1 01 74 32 31 c0 89 44 04 40 88 44 ff 89 |7...t21..D.@.D..| 000000b0 44 02 c7 04 10 00 66 8b 1e 5c 7c 66 89 5c 08 66 |D.....f..\|f.\.f| 000000c0 8b 1e 60 7c 66 89 5c 0c c7 44 06 00 70 b4 42 cd |..`|f.\..D..p.B.| 000000d0 13 72 05 bb 00 70 eb 76 b4 08 cd 13 73 0d 5a 84 |.r...p.v....s.Z.| 000000e0 d2 0f 83 de 00 be 85 7d e9 82 00 66 0f b6 c6 88 |.......}...f....| 000000f0 64 ff 40 66 89 44 04 0f b6 d1 c1 e2 02 88 e8 88 |d.@f.D..........| 00000100 f4 40 89 44 08 0f b6 c2 c0 e8 02 66 89 04 66 a1 |.@.D.......f..f.| 00000110 60 7c 66 09 c0 75 4e 66 a1 5c 7c 66 31 d2 66 f7 |`|f..uNf.\|f1.f.| 00000120 34 88 d1 31 d2 66 f7 74 04 3b 44 08 7d 37 fe c1 |4..1.f.t.;D.}7..| 00000130 88 c5 30 c0 c1 e8 02 08 c1 88 d0 5a 88 c6 bb 00 |..0........Z....| 00000140 70 8e c3 31 db b8 01 02 cd 13 72 1e 8c c3 60 1e |p..1......r...`.| 00000150 b9 00 01 8e db 31 f6 bf 00 80 8e c6 fc f3 a5 1f |.....1..........| 00000160 61 ff 26 5a 7c be 80 7d eb 03 be 8f 7d e8 34 00 |a.&Z|..}....}.4.| 00000170 be 94 7d e8 2e 00 cd 18 eb fe 47 52 55 42 20 00 |..}.......GRUB .| 00000180 47 65 6f 6d 00 48 61 72 64 20 44 69 73 6b 00 52 |Geom.Hard Disk.R| 00000190 65 61 64 00 20 45 72 72 6f 72 0d 0a 00 bb 01 00 |ead. Error......| 000001a0 b4 0e cd 10 ac 3c 00 75 f4 c3 00 00 00 00 00 00 |.....<.u........| 000001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001c0 01 00 ee fe ff ff 01 00 00 00 ff ff ff ff 00 00 |................| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 [root@yinzhengjie.com ~]#
4>.将小写字母转换为大写
[root@yinzhengjie.com ~]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Mon Jan 20 04:18:36 2020 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/centos-root / xfs defaults 0 0 UUID=1865a93f-6113-4097-89dc-8c4ea5fdf68c /boot xfs defaults 0 0 #Add by yinzhengjie /dev/mapper/centos-yinzhengjie /yinzhengjie xfs defaults,noatime,nodiratime 0 0 UUID=075b12f8-0a1f-4aef-a393-3f8fb6240e43 /mnt/sdb5 ext4 defaults,noexec 0 0 /boot /mnt/boot none bind 0 0 /yinzhengjie/data/ext4file /mnt/ext4 ext4 loop 0 0 #/dev/sr0 /mnt/cdrom iso9660 defaults 0 0 #Add by yinzhengjie for mount "/home". UUID=2307c9c5-f7b1-4a2b-b9e9-46d89a9c7c81 /home xfs defaults 0 0 [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# dd if=/etc/fstab of=/tmp/fstab.bak conv=ucase #将"/etc/fstab"文件的字符转换为大写并写入到"/tmp/fstab.bak"文件中 1+1 records in 1+1 records out 868 bytes (868 B) copied, 0.000140742 s, 6.2 MB/s [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat /tmp/fstab.bak # # /ETC/FSTAB # CREATED BY ANACONDA ON MON JAN 20 04:18:36 2020 # # ACCESSIBLE FILESYSTEMS, BY REFERENCE, ARE MAINTAINED UNDER '/DEV/DISK' # SEE MAN PAGES FSTAB(5), FINDFS(8), MOUNT(8) AND/OR BLKID(8) FOR MORE INFO # /DEV/MAPPER/CENTOS-ROOT / XFS DEFAULTS 0 0 UUID=1865A93F-6113-4097-89DC-8C4EA5FDF68C /BOOT XFS DEFAULTS 0 0 #ADD BY YINZHENGJIE /DEV/MAPPER/CENTOS-YINZHENGJIE /YINZHENGJIE XFS DEFAULTS,NOATIME,NODIRATIME 0 0 UUID=075B12F8-0A1F-4AEF-A393-3F8FB6240E43 /MNT/SDB5 EXT4 DEFAULTS,NOEXEC 0 0 /BOOT /MNT/BOOT NONE BIND 0 0 /YINZHENGJIE/DATA/EXT4FILE /MNT/EXT4 EXT4 LOOP 0 0 #/DEV/SR0 /MNT/CDROM ISO9660 DEFAULTS 0 0 #ADD BY YINZHENGJIE FOR MOUNT "/HOME". UUID=2307C9C5-F7B1-4A2B-B9E9-46D89A9C7C81 /HOME XFS DEFAULTS 0 0 [root@yinzhengjie.com ~]#
5>.不截断输出文件(标准输出指定的是普通文件默认会被截断，但设备并不会截断哟)
[root@yinzhengjie.com ~]# cat f1.txt ABCEDFGHIJKLMN [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f2.txt 12345 [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# dd if=f2.txt of=f1.txt bs=1 count=3 skip=2 seek=5 3+0 records in 3+0 records out 3 bytes (3 B) copied, 0.000268328 s, 11.2 kB/s [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f2.txt 12345 [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f1.txt #很明显，f1.txt文件内容被截断啦~ ABCED345[root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# cat f1.txt-bak ABCEDFGHIJKLMN [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f2.txt-bak 12345 [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# dd if=f2.txt-bak of=f1.txt-bak bs=1 count=3 skip=2 seek=5 conv=notrunc #添加不被截断参数 3+0 records in 3+0 records out 3 bytes (3 B) copied, 0.000123465 s, 24.3 kB/s [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f2.txt-bak 12345 [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# cat f1.txt-bak #很明显，目标文件并未被截断 ABCED345IJKLMN [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]#
6>.使用dd命令用于备份和恢复
备份操作: 将本地的/dev/sdx整盘备份到/dev/sdy: dd if=/dev/sdx of=/dev/sdy 将/dev/sdx全盘数据备份到指定路径的image文件: dd if=/dev/sdx of=/path/to/image 备份/dev/sdx全盘数据，并利用gzip压缩，保存到指定路径 dd if=/dev/sdx | gzip >/path/to/image.gz 恢复操作： 将备份文件恢复到指定盘 dd if=/path/to/image of=/dev/sdx 将压缩的备份文件恢复到指定盘: gzip -dc /path/to/image.gz | dd of=/dev/sdx 温馨提示: 当硬盘较长时间（比如1,2年）放置不使用后，磁盘上会产生消磁点。当磁头读到这些区域时会遇到困难，并可能导致I/O错误。当这种情况影响到硬盘的第一个扇区时，可能导致硬盘报废。 下边的命令有可能使这些数据起死回生,且这个过程是安全高效的. dd if=/dev/sda of=/dev/sda
7>.拷贝内存资料到硬盘
将内存里的数据拷贝到root目录下的mem.bin文件: dd if=/dev/mem of=/root/mem.bin bs=1024
8>.从光盘拷贝iso镜像
拷贝光盘数据到root文件夹下，并保存为cd.iso文件:
dd if=/dev/cdrom of=/root/cd.iso
9>.销毁磁盘数据
利用随机的数据填充硬盘，在某些必要的场合可以用来销毁数据，执行此操作以后，/dev/sda1将无法挂载，创建和拷贝操作无法执行:
dd if=/dev/urandom of=/dev/sda1
10>.得到最恰当的block size
存储相同大小文件，通过比较dd指令输出中命令的执行时间，即可确定系统最佳的block size大小。通常使用默认4K即可。
[root@yinzhengjie.com ~]# dd if=/dev/zero of=/root/1Gb.file bs=1024 count=1000000 1000000+0 records in 1000000+0 records out 1024000000 bytes (1.0 GB) copied, 8.54313 s, 120 MB/s [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# rm -rf /root/1Gb.file [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# dd if=/dev/zero of=/root/1Gb.file bs=2048 count=500000 500000+0 records in 500000+0 records out 1024000000 bytes (1.0 GB) copied, 1.30068 s, 787 MB/s [root@yinzhengjie.com ~]#
[root@yinzhengjie.com ~]# rm -rf /root/1Gb.file [root@yinzhengjie.com ~]# [root@yinzhengjie.com ~]# dd if=/dev/zero of=/root/1Gb.file bs=4096 count=250000 250000+0 records in 250000+0 records out 1024000000 bytes (1.0 GB) copied, 0.880223 s, 1.2 GB/s [root@yinzhengjie.com ~]#
11>.测试硬盘写速度
[root@yinzhengjie.com ~]# dd if=/dev/zero of=/root/10Gb.file bs=1024 count=10000000 #写一个10G的测试文件，观察写入磁盘写入速度的大小。 10000000+0 records in 10000000+0 records out 10240000000 bytes (10 GB) copied, 87.2831 s, 117 MB/s [root@yinzhengjie.com ~]#
12>.测试硬盘读速度
[root@yinzhengjie.com ~]# dd if=/root/10Gb.file bs=64k | dd of=/dev/null #将上一步生成的10G文件读取，观察读取速度的大小 156250+0 records in 156250+0 records out 10240000000 bytes (10 GB) copied, 38.9709 s, 263 MB/s 20000000+0 records in 20000000+0 records out 10240000000 bytes (10 GB) copied, 38.9712 s, 263 MB/s [root@yinzhengjie.com ~]#
13>.博主推荐阅读
Linux测试硬盘读性能的常用工具-hdparm和dd俩搭档: https://www.cnblogs.com/yinzhengjie/p/9935478.html
本文来自博客园，作者：尹正杰，转载请注明原文链接：https://www.cnblogs.com/yinzhengjie/p/12903198.html，个人微信: "JasonYin2020"（添加时请备注来源及意图备注，有偿付费）
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