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linux删除的文件如何恢复？

程序员文章站 2022-03-27 16:57:54
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linux删除的文件如何恢复？下面本篇文章给大家介绍一下恢复Linux删除文件的方法。有一定的参考价值，有需要的朋友可以参考一下，希望对大家有所帮助。

linux删除的文件如何恢复？

linux不像windows有个回收站，使用rm -rf *基本上文件是找不回来的。

那么问题来了：

对于linux下误删的文件，我们是否真的无法通过软件进行恢复呢?

答案当然是否定的，对于误删的文件，我们还是能通过软件恢复过来的。对于误删文件还原可以分为两种情况:

  • 一种是删除以后在进程存在删除信息

  • 一种是删除以后进程都找不到，只有借助于工具还原。

接下来以例子分别解说下两种不同的误删还原方式：

误删除文件进程还在的情况:

这种一般是有活动的进程存在持续标准输入或输出，到时文件被删除后，进程PID依旧存在。这也是有些服务器删除一些文件但是磁盘不释放的原因。

打开一个终端对一个测试文件做cat追加操作：

[root@docking ~]# echo "This is DeleteFile test." > deletefile.txt
[root@docking ~]# ls
deletefile.txt
[root@docking ~]# cat >> deletefile.txt 
Add SomeLine into deletefile for fun.

打开另外一个终端查看这个文件可以清楚看到内容：

[root@docking ~]# ls
deletefile.txt
[root@docking ~]# cat deletefile.txt 
This is DeleteFile test.
Add SomeLine into deletefile for fun.

此时，删除文件rm -f deletefile.txt

[root@docking ~]# rm -f deletefile.txt 
[root@docking ~]# ls
#命令查看这个目录，文件已经不存在了，那么现在我们将其恢复出来。

  • lsof查看删除的文件进程是否还存在。

  • 如没有安装请自行yum install lsof或者apt-get install lsof

1、类似这种情况，我们可以先lsof查看删除的文件 是否还在

[root@docking ~]# lsof | grep deletefile
cat       21796          root    1w      REG              253,1        63     138860 /root/deletefile.txt (deleted)

2、恢复cp /proc/pid/fd/1 /指定目录/文件名

进入 进程目录，一般是进入/proc/pid/fd/,针对当前情况：

[root@docking ~]# cd /proc/21796/fd
[root@docking fd]# ll
总用量 0
lrwx------ 1 root root 64 1月  18 22:21 0 -> /dev/pts/0
l-wx------ 1 root root 64 1月  18 22:21 1 -> /root/deletefile.txt (deleted)
lrwx------ 1 root root 64 1月  18 22:21 2 -> /dev/pts/0

恢复操作：

[root@docking fd]# cp 1 ~/deletefile.txt.backup
[root@docking fd]# cat ~/deletefile.txt.backup 
This is DeleteFile test.
Add SomeLine into deletefile for fun.

3、恢复完成。

误删除的文件进程已经不存在，借助于工具还原

准备一些文件目录

#准备一份挂载的盘
mkdir backuptest
cd backuptest
mkdir deletetest
mkdir deletetest/innerfolder
echo "Delete a folder test." > deletetest/innerfolder/deletefile.txt 

echo "tcpdump:x:172:72::/:/sbin/nologin" > tmppasswd

最后准备的目录结构如下：

taroballs@taroballs-PC:/media/taroballs/taroballs/backuptest$ cd ..
taroballs@taroballs-PC:/media/taroballs/taroballs$ tree backuptest/
backuptest/
├── deletetest
│   └── innerfolder
│       └── deletefile.txt
└── tmppasswd

2 directories, 2 files

现在开始删除该目录rm -rf backuptest/

taroballs@taroballs-PC:/media/taroballs/taroballs$ rm -rf backuptest/
taroballs@taroballs-PC:/media/taroballs/taroballs$  ls  -l
总用量 0

这种情况一般是没有守护进行或者后台进程对其持续输入，所以删除就真的删除了。lsof也看不到，故需要采用工具进行恢复。

现在开始进行误删除文件的恢复。

我们采用的工具是extundelete第三方工具。恢复步骤以及注意事项如下：

  • 停止对当前分区做任何操作，防止inode被覆盖。inode被覆盖基本就告别恢复了。

  • 夸张一点讲，比如停止所在分区的服务，卸载目录所在的设备，有必要的情况下都可以断网。

  • 通过dd命令对 当前分区进行备份，防止第三方软件恢复失败导致数据丢失。

  • 适合数据非常重要的情况，这里是例子，所以就没有备份，如备份可以考虑如下方式：dd if=/path/filename of=/dev/vdc1

  • 通过umount命令，对当前设备分区卸载。或者fuser 命令umount /dev/vdb1

  • 如果提示设备busy，可以用fuser命令强制卸载：fuser -m -v -i -k ./

  • 下载第三方工具extundelete安装，搜索误删除的文件进行还原

extundelete工具安装

extundelete下载地址：http://extundelete.sourceforge.net/

wget https://nchc.dl.sourceforge.net/project/extundelete/extundelete/0.2.4/extundelete-0.2.4.tar.bz2

解压该文件tar jxvf extundelete-0.2.4.tar.bz2

若报这种错误

[root@docking ~]# tar jxvf extundelete-0.2.4.tar.bz2 
tar (child): bzip2：无法 exec: 没有那个文件或目录
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now

则使用yum -y install bzip2进行解决

[root@docking ~]# tar jxvf extundelete-0.2.4.tar.bz2 
extundelete-0.2.4/
extundelete-0.2.4/acinclude.m4
extundelete-0.2.4/missing
extundelete-0.2.4/autogen.sh
extundelete-0.2.4/aclocal.m4
extundelete-0.2.4/configure
extundelete-0.2.4/LICENSE
extundelete-0.2.4/README
...................................................
cd  extundelete-0.2.4
./configure

若这步骤报错

[root@docking extundelete-0.2.4]# ./configure 
Configuring extundelete 0.2.4
configure: error: in `/root/extundelete-0.2.4':
configure: error: C++ compiler cannot create executables
See `config.log' for more details

则使用yum -y install gcc-c++解决.

若执行上一步仍然报错，

[root@docking extundelete-0.2.4]# ./configure 
Configuring extundelete 0.2.4
configure: error: Can't find ext2fs library

则使用yum -y install e2fsprogs e2fsprogs-devel来解决。
#Ubuntu的解决办法为sudo apt-get install e2fslibs-dev e2fslibs-dev

不出意外的话到这里应该configure能够顺利完成.

[root@docking extundelete-0.2.4]# ./configure 
Configuring extundelete 0.2.4
Writing generated files to disk
[root@docking extundelete-0.2.4]#

最后make然后 make install

[root@docking extundelete-0.2.4]# make
make -s all-recursive
Making all in src
extundelete.cc: 在函数‘ext2_ino_t find_inode(ext2_filsys, ext2_filsys, ext2_inode*, std::string, int)’中:
extundelete.cc:1272:29: 警告：在 {} 内将‘search_flags’从‘int’转换为较窄的类型‘ext2_ino_t {aka unsigned int}’ [-Wnarrowing]
    buf, match_name2, priv, 0};
                             ^
[root@docking extundelete-0.2.4]# make install
Making install in src
  /usr/bin/install -c extundelete '/usr/local/bin'

extundelete安装完成.

扫描误删除的文件：

使用df -lh查看挂载：

taroballs@taroballs-PC:~$ df -lh
文件系统        容量  已用  可用 已用% 挂载点
udev            1.9G     0  1.9G    0% /dev
tmpfs           387M  1.8M  385M    1% /run
/dev/sda2        92G   61G   26G   71% /
tmpfs           1.9G   49M  1.9G    3% /dev/shm
tmpfs           5.0M  4.0K  5.0M    1% /run/lock
tmpfs           1.9G     0  1.9G    0% /sys/fs/cgroup
/dev/sda3       104G   56G   44G   57% /home
tmpfs           387M   40K  387M    1% /run/user/1000
/dev/sda4        70G   20G   47G   30% /media/taroballs/d8423f8c-d687-4c03-a7c8-06a7fb57f96d
/dev/sdb1       6.8G  4.1G  2.8G   60% /media/taroballs/taroballs
/dev/sr0        4.0G  4.0G     0  100% /media/taroballs/2018-01-16-12-36-00-00
taroballs@taroballs-PC:~$ cd /media/taroballs/taroballs/
taroballs@taroballs-PC:/media/taroballs/taroballs$

可以看到，我们的目录/media/taroballs/taroballs

挂载到/dev/sdb1 这个文件系统中.

umount我们的挂载盘

比如：

taroballs@taroballs-PC:~$ df -lh | grep /dev/sdb1
/dev/sdb1       6.8G  4.1G  2.8G   60% /media/taroballs/taroballs

umount这个目录

taroballs@taroballs-PC:~$ umount /media/taroballs/taroballs
taroballs@taroballs-PC:~$ df -lh | grep /dev/sdb1
taroballs@taroballs-PC:~$ 
#记得删除一定要后umount哦，不然二次写入谁也帮不了你呢。

通过inode节点恢复

taroballs@taroballs-PC:~$ mkdir recovertest
taroballs@taroballs-PC:~$ cd recovertest/
taroballs@taroballs-PC:~/recovertest$

执行恢复extundelete /dev/sdb1 --inode 2

taroballs@taroballs-PC:/media/taroballs/taroballs$ sudo extundelete /dev/sdb1 --inode 2
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 8 groups loaded.
Group: 0
Contents of inode 2:
 
.
.省略N行
 
File name                                       | Inode number | Deleted status
.                                                 2
..                                                2
deletetest                                        12             Deleted
tmppasswd                                            14             Deleted

通过扫描发现了我们删除的文件夹，现在执行恢复操作。

（1）恢复单一文件tmppasswd

taroballs@taroballs-PC:~/recovertest$  extundelete /dev/sdb1 --restore-file passwd   
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 8 groups loaded.
Loading journal descriptors ... 46 descriptors loaded.
Successfully restored file tmppasswd

恢复文件是放到了当前目录RECOVERED_FILES。

查看恢复的文件：

taroballs@taroballs-PC:~/recovertest$ cat tmppasswd 
tcpdump:x:172:72::/:/sbin/nologin

（2）恢复目录deletetest

extundelete /dev/sdb1 --restore-directory  deletetest
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 8 groups loaded.
Loading journal descriptors ... 46 descriptors loaded.
Searching for recoverable inodes in directory deletetest ... 
5 recoverable inodes found.
Looking through the directory structure for deleted files ...

（3）恢复所有

taroballs@taroballs-PC:~/recovertest$ extundelete /dev/sdb1 --restore-all
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 8 groups loaded.
Loading journal descriptors ... 46 descriptors loaded.
Searching for recoverable inodes in directory / ... 
5 recoverable inodes found.
Looking through the directory structure for deleted files ... 
0 recoverable inodes still lost. 
taroballs@taroballs-PC:~/recovertest$ tree 
backuptest/
├── deletetest
│   └── innerfolder
│       └── deletefile.txt
└── tmppasswd
2 directories, 2 files

（4）恢复指定inode

taroballs@taroballs-PC:~/recovertest$ extundelete /dev/sdb1 --restore-inode 14
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 8 groups loaded.
Loading journal descriptors ... 46 descriptors loaded.
taroballs@taroballs-PC:~/recovertest$ cat file.14 
tcpdump:x:172:72::/:/sbin/nologin
#注意恢复inode的时候，恢复 出来的文件名和之前不一样，需要单独进行改名。

最后附上extundelete的用法:

$ extundelete --help
Usage: extundelete [options] [--] device-file
Options:
  --version, -[vV]       Print version and exit successfully.
  --help,                Print this help and exit successfully.
  --superblock           Print contents of superblock in addition to the rest.
                         If no action is specified then this option is implied.
  --journal              Show content of journal.
  --after dtime          Only process entries deleted on or after 'dtime'.
  --before dtime         Only process entries deleted before 'dtime'.Actions:
  --inode ino            Show info on inode 'ino'.
  --block blk            Show info on block 'blk'.
  --restore-inode ino[,ino,...]
                         Restore the file(s) with known inode number 'ino'.
                         The restored files are created in ./RECOVERED_FILES                         with their inode number as extension (ie, file.12345).
  --restore-file 'path'  Will restore file 'path'. 'path' is relative to root
                         of the partition and does not start with a '/'
                         The restored file is created in the current
                         directory as 'RECOVERED_FILES/path'.
  --restore-files 'path' Will restore files which are listed in the file 'path'.
                         Each filename should be in the same format as an option
                         to --restore-file, and there should be one per line.
  --restore-directory 'path'
                         Will restore directory 'path'. 'path' is relative to the
                         root directory of the file system.  The restored
                         directory is created in the output directory as 'path'.
  --restore-all          Attempts to restore everything.
  -j journal             Reads an external journal from the named file.
  -b blocknumber         Uses the backup superblock at blocknumber when opening
                         the file system.
  -B blocksize           Uses blocksize as the block size when opening the file
                         system.  The number should be the number of bytes.
  --log 0                Make the program silent.
  --log filename         Logs all messages to filename.--log D1=0,D2=filename   Custom control of log messages with comma-separated
   Examples below:       list of options.  Dn must be one of info, warn, or   --log info,error      error.  Omission of the '=name' results in messages   --log warn=0          with the specified level to be logged to the console.
   --log error=filename  If the parameter is '=0', logging for the specified
                         level will be turned off.  If the parameter is
                         '=filename', messages with that level will be written
                         to filename.
   -o directory          Save the recovered files to the named directory.
                         The restored files are created in a directory
                         named 'RECOVERED_FILES/' by default.

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