linux下extundelete恢复ext4删除的文件

linux文件组成: 文件名, inode(存放元数据), block(存放具体数据)
用stat命令可以看到文件相关的权限以及inode等信息
stat passwd 
  File: `passwd'
  Size: 1876            Blocks: 8          IO Block: 4096   regular file
Device: fd00h/64768d    Inode: 14          Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2015-12-04 16:43:36.154319045 +0800   //atime 文件的访问时间
Modify: 2015-12-04 16:38:17.502319274 +0800   //mtime 修改文件的内容时间  如：echo "aaaaa" > passwd
Change: 2015-12-04 16:43:28.200319096 +0800   //ctime 需改文件的属性时间  如：chmod u+x passwd 


extundelete恢复实例：


查看文件系统挂载：
df -Th
Filesystem           Type   Size  Used Avail Use% Mounted on
/dev/sda1            ext4    32G  3.8G   27G  13% /
tmpfs                tmpfs   32G  4.0K   32G   1% /dev/shm
/dev/sda3            ext4    96G  5.5G   85G   7% /opt
/dev/oczpcie_7_0_ssd2
                     ext4   204G  6.9G  187G   4% /data02
/dev/mapper/cachedev ext4   275G  2.3G  259G   1% /data01


复制一个passwd文件做测试：
cp /etc/passwd /data01/
ls
5281  lost+found  mongo.conf  mongodb_log  passwd  test1.file  test2.file






安装extundelete:
需要安装e2fs
yum install -y e2fsprogs* e2fslibs*
下载安装包
wget http://nchc.dl.sourceforge.net/project/extundelete/extundelete/0.2.4/extundelete-0.2.4.tar.bz2
tar -jxvf extundelete-0.2.4.tar.bz2
cd extundelete-0.2.4
./configure
make -j 8
make install




删除文件：
rm -f /data01/passwd


umount或者改为read only


umount  /dev/mapper/cachedev  /data01
或者
mount -o remount,ro /dev/mapper/cachedev


extundelete /dev/mapper/cachedev --inode 2
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 2235 groups loaded.
Group: 0
Contents of inode 2:
0000 | ed 41 00 00 00 10 00 00 fd 4f 61 56 f7 4f 61 56 | .A.......OaV.OaV
0010 | f7 4f 61 56 00 00 00 00 00 00 05 00 08 00 00 00 | .OaV............
0020 | 00 00 00 00 1d 00 00 00 21 24 00 00 00 00 00 00 | ........!$......
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 80 59 13 00 80 59 13 00 c8 e7 e0 1d | .....Y...Y......
0090 | 15 1f e4 55 00 00 00 00 00 00 00 00 00 00 00 00 | ...U............
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: 1449218045
Creation time: 1449218039
Modification time: 1449218039
Deletion Time: 0
Low 16 bits of Group Id: 0
Links count: 5
Blocks count: 8
File flags: 0
File version (for NFS): 0
File ACL: 0
Directory ACL: 0
Fragment address: 0
Direct blocks: 9249, 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
test1.file                                        12
test2.file                                        13
5281                                              12320769
mongo.conf                                        15
mongodb_log                                       262145
passwd                                            14             Deleted
aa.txt                                            16             Deleted


可以看到passwd和aa.txt文件都被删除，那么我们只恢复passwd文件：
cd /data02   //必须不能再同一个分区，需要在其他分区做恢复
extundelete /dev/mapper/cachedev --restore-file passwd
NOTICE: Extended attributes are not restored.
Loading filesystem metadata ... 2235 groups loaded.
Loading journal descriptors ... 5217 descriptors loaded.
Successfully restored file passwd


也可以通过inode恢复 extundelete /dev/mapper/cachedev --restore-inode 14    //14就是之前看到的inode number


ls //可以看到产生了一个叫RECOVERED_FILES的恢复目录，我们恢复的文件就在这个目录之下
arch  lost+found  peer_arch  RECOVERED_FILES  test1.file  test2.file
cd /data02/RECOVERED_FILES/ 
ls 
passwd
diff /etc/passwd passwd  //两个文件没区别
然后重新挂载分区或者改为读写模式
mount -o remount,rw /dev/mapper/cachedev
mv passwd  /data01/
cd /data01/
ls
5281  lost+found  mongo.conf  mongodb_log  passwd  test1.file  test2.file


到此恢复结束。