一：前言
在Linux中，我们通常会因为误删除文件而感到烦恼，rm -rf +文件 rf参数简直就是每个运维的噩梦，但是大家想过没，为什么删除文件那么快呢，为什么我们copy文件的时候那么慢。
其实不管大家是rm 还是rm -rf都是删除的文件名字而已，数据还是保存在磁盘扇区里面的，当然这只是我的理解，那么删除后我们要怎么恢复呢，下面实验将进行对extundelete工具的简单操作介绍，
二：实验环境
系统：CentOS6.4_x64-mini.iso
工具选择： extundelete-0.2.4.tar.bz2
extundelete官网：http://extundelete.sourceforge.net/
备注：这里我全文全部为Linux命令，没有任何图片，加一个图片到blogs里面很累的。
再者环境我说明一下，我这里的实验目录是单独挂载到一个硬盘上的，不然搞得大家看不懂就很不好了，
说下我为什么挂载一个硬盘上呢，大家想下，企业中了为了安全的考虑，肯定会把数据盘和系统盘分开。
删除了数据盘的数据就必须马上umount下，不然数据二次写入，就是大牛来了也帮不了你了。这点和Windows一样，我想都会懂的。
三：实验前准备
创建目录，copy文件。
[root@nginx ~]#mkdir /yang [root@nginx ~]# mkfs.ext4 /dev/sdb [root@nginx ~]# mount /dev/sdb /yang/ [root@nginx ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda2 9.5G 3.6G 5.5G 39% / tmpfs 242M 0 242M 0% /dev/shm /dev/sda1 190M 27M 153M 15% /boot /dev/sdb 4.8G 10M 4.6G 1% /yang [root@nginx ~]# cp /etc/hosts /yang/ [root@nginx ~]# cp /etc/passwd /yang/ [root@nginx ~]# mkdir -p /yang/data1/ [root@nginx ~]# mkdir -p /yang/data2/ [root@nginx ~]# echo "data1.txt" > /yang/data1/data1.txt [root@nginx ~]# echo "data2.txt" > /yang/data2/data2.txt [root@nginx ~]# ls -r /yang/* /yang/passwd /yang/hosts /yang/lost+found: /yang/data2: data2.txt /yang/data1: data1.txt ###以上为我实验环境的准备，命令都很简单，最后查看文件输出结果###
四、下载安装extundelete
[root@nginx ~]#wget http://internode.dl.sourceforge.net/project/extundelete/extundelete/0.2.4/extundelete-0.2.4.tar.bz2 [root@nginx ~]# tar jxvf extundelete-0.2.4.tar.bz2 [root@nginx ~]# cd extundelete-0.2.4 [root@nginx extundelete-0.2.4]# ls acinclude.m4 autogen.sh config.log configure.ac install-sh Makefile.am missing src aclocal.m4 config.h.in configure depcomp LICENSE Makefile.in README [root@nginx extundelete-0.2.4]# ./configure Configuring extundelete 0.2.4 configure: error: Can't find ext2fs library ###好的，到这里看到报错，怎么办呢，根据报错解决了###
这里报错说找不到ext2fs，找不到就装一个呗，怎么装呢，yum? 首先要确定下这个包，yum直接安装ext2fs肯定是没有的，接下来我们既然没那么多经验，不知道包名字，我们就rpm找就可以了，简单明了。
[root@nginx extundelete-0.2.4]# mount /dev/cdrom /mnt/ mount: block device /dev/sr0 is write-protected, mounting read-only [root@nginx extundelete-0.2.4]# cd /mnt/ [root@nginx mnt]# ls CentOS_BuildTag GPL Packages RPM-GPG-KEY-CentOS-6 RPM-GPG-KEY-CentOS-Testing-6 EFI images RELEASE-NOTES-en-US.html RPM-GPG-KEY-CentOS-Debug-6 TRANS.TBL EULA isolinux repodata RPM-GPG-KEY-CentOS-Security-6 [root@nginx mnt]# cd Packages/ [root@nginx Packages]# ls *2fs* e2fsprogs-1.41.12-21.el6.x86_64.rpm e2fsprogs-devel-1.41.12-21.el6.x86_64.rpm e2fsprogs-libs-1.41.12-21.el6.x86_64.rpm e2fsprogs-devel-1.41.12-21.el6.i686.rpm e2fsprogs-libs-1.41.12-21.el6.i686.rpm [root@nginx Packages]# rpm -ivh e2fsprogs-1.41.12-21.el6.x86_64.rpm Preparing... ########################################### [100%] package e2fsprogs-1.41.12-21.el6.x86_64 is already installed [root@nginx Packages]# rpm -ivh e2fsprogs-devel-1.41.12-21.el6.x86_64.rpm Preparing... ########################################### [100%] 1:e2fsprogs-devel ########################################### [100%]
Ok，这里我安装成功了，我的是x64位系统，当然我要装x86_x64啦。接下来我们继续编译安装。
[root@nginx Packages]# cd /root/extundelete-0.2.4 [root@nginx extundelete-0.2.4]# ./configure Configuring extundelete 0.2.4 Writing generated files to disk [root@nginx extundelete-0.2.4]# echo $? 0 [root@nginx extundelete-0.2.4]# make && make install make -s all-recursive Making all in src extundelete.cc:571: warning: unused parameter ‘flags’ Making install in src /usr/bin/install -c extundelete '/usr/local/bin' [root@nginx extundelete-0.2.4]# ls /usr/local/bin/ Extundelete ########安装成功 我们开始删除文件来进行恢复测试#####
进行删除，恢复测试。记得删除后umount哦，不然二次写入谁也帮不了你呢。
[root@nginx ~]# rm -rf /yang/* [root@nginx ~]# ls /yang/* ls: cannot access /yang/*: No such file or directory [root@nginx ~]# ls /yang/ [root@nginx ~]#echo “这里可以看到我刚才删除了rm –rf /yang/*就没有任何东西了” [root@nginx ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda2 9.5G 3.6G 5.5G 40% / tmpfs 242M 0 242M 0% /dev/shm /dev/sda1 190M 27M 153M 15% /boot /dev/sdb 4.8G 10M 4.6G 1% /yang /dev/sr0 4.4G 4.4G 0 100% /mnt [root@nginx ~]# umount /yang/ [root@nginx ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda2 9.5G 3.6G 5.5G 40% / tmpfs 242M 0 242M 0% /dev/shm /dev/sda1 190M 27M 153M 15% /boot /dev/sr0 4.4G 4.4G 0 100% /mnt
五、恢复测试。恢复方式有很多，接下来简单说几个。
1、 通过inode节点恢复
什么是inode?这里建议大家去百度，其实笔者也不是很懂啦，哈哈，我只是会一些简单的。
[root@nginx ~]# mkdir /recover [root@nginx ~]# cd /recover/ [root@nginx recover]# ls [root@nginx recover]# extundelete /dev/sdb --inode 2 NOTICE: Extended attributes are not restored. Loading filesystem metadata ... 40 groups loaded. Group: 0 Contents of inode 2: 0000 | ed 41 00 00 00 10 00 00 b3 3f 79 57 af 3f 79 57 | .A.......?yW.?yW 0010 | af 3f 79 57 00 00 00 00 00 00 02 00 08 00 00 00 | .?yW............ 0020 | 00 00 00 00 09 00 00 00 61 21 00 00 00 00 00 00 | ........a!...... 0030 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 0040 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 0050 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 0060 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 0070 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 0080 | 1c 00 00 00 a8 c0 78 45 a8 c0 78 45 6c 66 f1 64 | ......xE..xElf.d 0090 | 27 3d 79 57 00 00 00 00 00 00 00 00 00 00 00 00 | '=yW............ 00a0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 00b0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 00c0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 00d0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 00e0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ 00f0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................ Inode is Allocated File mode: 16877 Low 16 bits of Owner Uid: 0 Size in bytes: 4096 Access time: 1467563955 Creation time: 1467563951 Modification time: 1467563951 Deletion Time: 0 Low 16 bits of Group Id: 0 Links count: 2 Blocks count: 8 File flags: 0 File version (for NFS): 0 File ACL: 0 Directory ACL: 0 Fragment address: 0 Direct blocks: 8545, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 Indirect block: 0 Double indirect block: 0 Triple indirect block: 0 File name | Inode number | Deleted status . 2 .. 2 lost+found 11 Deleted hosts 12 Deleted passwd 13 Deleted data1 131073 Deleted data2 131074 Deleted [root@nginx recover]# [root@nginx recover]# extundelete /dev/sdb --restore-inode 13 NOTICE: Extended attributes are not restored. Loading filesystem metadata ... 40 groups loaded. Loading journal descriptors ... 52 descriptors loaded. [root@nginx recover]# ls RECOVERED_FILES [root@nginx recover]# ls RECOVERED_FILES/ file.13 [root@nginx recover]# du -sh ./RECOVERED_FILES/file.13 4.0K ./RECOVERED_FILES/file.13 [root@nginx recover]# echo "这里我根据是inode的节点恢复的，当然这里有些人会不了解为什么是file.13，上面我inode节点对应的不是passwd文件？下面我们查看一下是否一样文件，再使用diff对比一下。"
原文件:
[root@nginx recover]# more /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin gopher:x:13:30:gopher:/var/gopher:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin rpc:x:32:32:Rpcbind Daemon:/var/cache/rpcbind:/sbin/nologin vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin abrt:x:173:173::/etc/abrt:/sbin/nologin saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin haldaemon:x:68:68:HAL daemon:/:/sbin/nologin ntp:x:38:38::/etc/ntp:/sbin/nologin radvd:x:75:75:radvd user:/:/sbin/nologin qemu:x:107:107:qemu user:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin tcpdump:x:72:72::/:/sbin/nologin oprofile:x:16:16:Special user account to be used by OProfile:/home/oprofile:/sbin/nologin www:x:600:600::/data1/app/services/nginx:/sbin/nologin [root@nginx recover]#
恢复出来的文件：
[root@nginx recover]# more RECOVERED_FILES/file.13 root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin adm:x:3:4:adm:/var/adm:/sbin/nologin lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin sync:x:5:0:sync:/sbin:/bin/sync shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown halt:x:7:0:halt:/sbin:/sbin/halt mail:x:8:12:mail:/var/spool/mail:/sbin/nologin uucp:x:10:14:uucp:/var/spool/uucp:/sbin/nologin operator:x:11:0:operator:/root:/sbin/nologin games:x:12:100:games:/usr/games:/sbin/nologin gopher:x:13:30:gopher:/var/gopher:/sbin/nologin ftp:x:14:50:FTP User:/var/ftp:/sbin/nologin nobody:x:99:99:Nobody:/:/sbin/nologin dbus:x:81:81:System message bus:/:/sbin/nologin rpc:x:32:32:Rpcbind Daemon:/var/cache/rpcbind:/sbin/nologin vcsa:x:69:69:virtual console memory owner:/dev:/sbin/nologin abrt:x:173:173::/etc/abrt:/sbin/nologin saslauth:x:499:76:Saslauthd user:/var/empty/saslauth:/sbin/nologin rpcuser:x:29:29:RPC Service User:/var/lib/nfs:/sbin/nologin nfsnobody:x:65534:65534:Anonymous NFS User:/var/lib/nfs:/sbin/nologin postfix:x:89:89::/var/spool/postfix:/sbin/nologin haldaemon:x:68:68:HAL daemon:/:/sbin/nologin ntp:x:38:38::/etc/ntp:/sbin/nologin radvd:x:75:75:radvd user:/:/sbin/nologin qemu:x:107:107:qemu user:/:/sbin/nologin sshd:x:74:74:Privilege-separated SSH:/var/empty/sshd:/sbin/nologin tcpdump:x:72:72::/:/sbin/nologin oprofile:x:16:16:Special user account to be used by OProfile:/home/oprofile:/sbin/nologin www:x:600:600::/data1/app/services/nginx:/sbin/nologin [root@nginx recover]# ##############输出的结果一模一样############
再者我们使用diff对比一下文件，diff命令不懂？ 没问题啊，一样啊去百度啊，因为笔者也不了解，嘿嘿。逗逼一下，不然写着很累的。
[root@nginx recover]# diff /etc/passwd ./RECOVERED_FILES/file.13 [root@nginx recover]# echo $? 0 [root@nginx recover]#echo “这里返回结果就是0,没有报错，就是成功了，对比一样，记住，在Linux中没有信息就是最好的信息。”
2、 根据文件名来恢复
[root@nginx recover]# extundelete /dev/sdb --restore-file hosts NOTICE: Extended attributes are not restored. Loading filesystem metadata ... 40 groups loaded. Loading journal descriptors ... 52 descriptors loaded. Successfully restored file hosts [root@nginx recover]# ls RECOVERED_FILES [root@nginx recover]# ls RECOVERED_FILES/ file.13 hosts [root@nginx recover]# diff /etc/hosts ./RECOVERED_FILES/hosts [root@nginx recover]# echo $? 0 [root@nginx recover]#echo“对比一样还是恢复成功了。”
3、根据目录来恢复
[root@nginx recover]# extundelete /dev/sdb --restore-directory data1 NOTICE: Extended attributes are not restored. Loading filesystem metadata ... 40 groups loaded. Loading journal descriptors ... 52 descriptors loaded. Searching for recoverable inodes in directory data1 ... 7 recoverable inodes found. Looking through the directory structure for deleted files ... 6 recoverable inodes still lost. [root@nginx recover]# ls ./RECOVERED_FILES/ data1 file.13 hosts [root@nginx recover]# ls ./RECOVERED_FILES/data1/ data1.txt [root@nginx recover]# echo “到这里目录测试也是可以恢复成功，里面文件也是我之前的文件，那么如果有人说我的文件太多了我想恢复所有的，这样操作是不是太麻烦了，没问题，下面我来教大家怎么恢复所有的，就是更改下参数。”
4、恢复全部文件。
我先给之前恢复的文件都删除了，下面看是不是可以正常恢复成功所有的文件
[root@nginx recover]# rm -rf RECOVERED_FILES/ [root@nginx recover]# ls [root@nginx recover]# extundelete /dev/sdb --restore-all NOTICE: Extended attributes are not restored. Loading filesystem metadata ... 40 groups loaded. Loading journal descriptors ... 52 descriptors loaded. Searching for recoverable inodes in directory / ... 7 recoverable inodes found. Looking through the directory structure for deleted files ... 0 recoverable inodes still lost. [root@nginx recover]# ls RECOVERED_FILES [root@nginx recover]# ls -r ./RECOVERED_FILES/ passwd hosts data2 data1 [root@nginx recover]#echo “可以看到我删除后所有的都恢复过来了”
啊~~~到这里总算是告一段落了，实在不懂的直接问我就可以了，我也是今天才学的。感谢大家~