Linux恢復誤刪除的文件或者目錄

時間 2019-12-07

標籤 linux 恢復刪除文件或者目錄欄目 Linux 简体版

原文原文鏈接

2017 年 2 月 1 日 GitLab 數據庫被誤刪引發了廣大爭議.node

linux不像windows有個回收站，使用rm -rf *基本上文件是找不回來的。linux

那麼問題來了：
對於linux下誤刪的文件，咱們是否真的沒法經過軟件進行恢復呢?c++

答案固然是否認的，對於誤刪的文件，咱們仍是能經過軟件恢復過來的。對於誤刪文件還原能夠分爲兩種狀況:數據庫

一種是刪除之後在進程存在刪除信息
一種是刪除之後進程都找不到，只有藉助於工具還原。

接下來以例子分別解說下兩種不一樣的誤刪還原方式：windows

誤刪除文件進程還在的狀況:
這種通常是有活動的進程存在持續標準輸入或輸出，到時文件被刪除後，進程PID依舊存在。這也是有些服務器刪除一些文件可是磁盤不釋放的緣由。服務器

打開一個終端對一個測試文件作cat追加操做：tcp

[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.

打開另一個終端查看這個文件能夠清楚看到內容：函數

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

此時，刪除文件rm -f deletefile.txt工具

[root@docking ~]# rm -f deletefile.txt 
[root@docking ~]# ls
#命令查看這個目錄，文件已經不存在了，那麼如今咱們將其恢復出來。

lsof查看刪除的文件進程是否還存在。
如沒有安裝請自行yum install lsof或者apt-get install lsof
1.相似這種狀況，咱們能夠先lsof查看刪除的文件是否還在

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

2.恢復cp /proc/pid/fd/1 /指定目錄/文件名
進入進程目錄，通常是進入/proc/pid/fd/,針對當前狀況：測試

[root@docking ~]# cd /proc/21796/fd
[root@docking fd]# ll
總用量 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

恢復操做：

[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.恢復完成。

誤刪除的文件進程已經不存在，藉助於工具還原
準備一些文件目錄

#準備一份掛載的盤
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

最後準備的目錄結構以下：

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

如今開始刪除該目錄rm -rf backuptest/

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

這種狀況通常是沒有守護進行或者後臺進程對其持續輸入，因此刪除就真的刪除了。lsof也看不到，故須要採用工具進行恢復。

如今開始進行誤刪除文件的恢復。

咱們採用的工具是extundelete第三方工具。恢復步驟以及注意事項以下：

中止對當前分區作任何操做，防止inode被覆蓋。inode被覆蓋基本就告別恢復了。
誇張一點講，好比中止所在分區的服務，卸載目錄所在的設備，有必要的狀況下均可以斷網。
經過dd命令對當前分區進行備份，防止第三方軟件恢復失敗致使數據丟失。
適合數據很是重要的狀況，這裏是例子，因此就沒有備份，如備份能夠考慮以下方式：dd if=/path/filename of=/dev/vdc1
經過umount命令，對當前設備分區卸載。或者fuser 命令umount /dev/vdb1
若是提示設備busy，能夠用fuser命令強制卸載：fuser -m -v -i -k ./
下載第三方工具extundelete安裝，搜索誤刪除的文件進行還原

extundelete工具安裝

extundelete下載地址：http://extundelete.sourceforge.net/

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

解壓該文件tar jxvf extundelete-0.2.4.tar.bz2

若報這種錯誤

[root@docking ~]# tar jxvf extundelete-0.2.4.tar.bz2 
tar (child): bzip2：沒法 exec: 沒有那個文件或目錄
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now

則使用yum -y install bzip2進行解決

[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

若這步驟報錯

[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

則使用yum -y install gcc-c++解決.

若執行上一步仍然報錯，

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

則使用yum -y install e2fsprogs e2fsprogs-devel來解決。
#Ubuntu的解決辦法爲sudo apt-get install e2fslibs-dev e2fslibs-dev

不出意外的話到這裏應該configure可以順利完成.

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

最後make而後 make install

[root@docking extundelete-0.2.4]# make
make -s all-recursive
Making all in src
extundelete.cc: 在函數‘ext2_ino_t find_inode(ext2_filsys, ext2_filsys, ext2_inode*, std::string, int)’中:
extundelete.cc:1272:29: 警告：在 {} 內將‘search_flags’從‘int’轉換爲較窄的類型‘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安裝完成.

掃描誤刪除的文件：

使用df -lh查看掛載：

taroballs@taroballs-PC:~$ df -lh
文件系統        容量  已用  可用 已用% 掛載點
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$

能夠看到，咱們的目錄/media/taroballs/taroballs
掛載到/dev/sdb1 這個文件系統中.

umount咱們的掛載盤
好比：

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

umount這個目錄

taroballs@taroballs-PC:~$ umount /media/taroballs/taroballs
taroballs@taroballs-PC:~$ df -lh | grep /dev/sdb1
taroballs@taroballs-PC:~$ 
#記得刪除必定要後umount哦，否則二次寫入誰也幫不了你呢。

經過inode節點恢復

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

執行恢復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

經過掃描發現了咱們刪除的文件夾，如今執行恢復操做。
（1）恢復單一文件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

恢復文件是放到了當前目錄RECOVERED_FILES。
查看恢復的文件：

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

（2）恢復目錄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）恢復全部

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）恢復指定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
#注意恢復inode的時候，恢復 出來的文件名和以前不同，須要單獨進行更名。

最後附上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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