9.2 KiB
Recovering deleted files on Linux with testdisk
This post describes testdisk, one of the tools that comes in handy for recovering recently deleted files (along with fixing partitions in other ways). Thinkstock
When you delete a file on a Linux system, it isn’t necessarily gone forever, especially if you just recently deleted it.
Unless you rubbed it out with a tool such as shred, the data will still be sitting on your disk—and one of the best tools for recovering deleted files, testdisk, can help you rescue it. While testdisk has a wide range of functionality including recovering lost or damaged partitions and making non-booting disks bootable again, it’s also frequently used to restore files that were deleted by mistake.
In this post, we’ll take a look at how you can recover deleted files using testdisk and what each step in the process looks like. Since the process requires quite a few steps, you’re likely to feel more comfortable running through them once you’ve done it a few times.
Installing testdisk
Install testdisk with commands like apt install testdisk or yum install testdisk. Interestingly, it’s not just a Linux tool but is also available for MacOS, Solaris and Windows as well.
Documentation is available at cgsecurity.org.
Recovering files
First of all, you have to be logged in as root or have sudo access to use testdisk. If you don’t have sudo access, you’ll get kicked out early in the process, and your logfile, if you chose to create one, will end up with a message like this in it:
TestDisk exited normally.
jdoe is not in the sudoers file. This incident will be reported.
When you recover deleted files with testdisk, you’re going to end up with the files being restored within the directory form which you started the tool and the files are going to belong to root. For this reason, I like to start in a directory like /home/recovery. Once the files are successfully restored and verified, they can be moved back to where they belong and have their ownership restored as well.
Make sure you can write in the directory you select to start in.
$ cd /home/recovery
$ testdisk
The first page of information presented by testdisk describes the tool and displays some options. At least initially, it’s a good idea to create the log file as it provides information that might prove useful. Here’s how:
Use arrow keys to select, then press Enter key:
>[ Create ] Create a new log file
[ Append ] Append information to log file
[ No Log ] Don’t record anything
The > on the left and the reversal of the font and background colors that you will see show the option that will be used once you press enter. In this example, we opted to create the log file.
You will then be prompted for your password (unless you very recently used sudo).
The next step is to select the disk partition in which the deleted file was stored (if not already highlighted). Use the up and down arrow keys as needed to move to it. Then tap the right arrow twice and press enter when Proceed is highlighted.
Select a media (use Arrow keys, then press Enter):
Disk /dev/sda - 120 GB / 111 GiB - SSD2SC120G1CS1754D117-551
>Disk /dev/sdb - 500 GB / 465 GiB - SAMSUNG HE502HJ
Disk /dev/loop0 - 13 MB / 13 MiB (RO)
Disk /dev/loop1 - 101 MB / 96 MiB (RO)
Disk /dev/loop10 - 148 MB / 141 MiB (RO)
Disk /dev/loop11 - 36 MB / 35 MiB (RO)
Disk /dev/loop12 - 52 MB / 49 MiB (RO)
Disk /dev/loop13 - 78 MB / 75 MiB (RO)
Disk /dev/loop14 - 173 MB / 165 MiB (RO)
Disk /dev/loop15 - 169 MB / 161 MiB (RO)
>[Previous] [ Next ] [Proceed ] [ Quit ]
In this example, the deleted file was in a home directory in /dev/sdb.
At this point, the partition type should already be selected by testdisk.
Disk /dev/sdb - 500 GB / 465 GiB - SAMSUNG HE502HJ
Please select the partition table type, press Enter when done.
[Intel ] Intel/PC partition
>[EFI GPT] EFI GPT partition map (Mac i386, some x86_64...)
[Humax ] Humax partition table
[Mac ] Apple partition map (legacy)
[None ] Non partitioned media
[Sun ] Sun Solaris partition
[XBox ] XBox partition
[Return ] Return to disk selection
In the next step, arrow down to “[ Advanced ] Filesystem Utils”.
[ Analyse ] Analyse current partition structure and search for lost partitions
>[ Advanced ] Filesystem Utils
[ Geometry ] Change disk geometry
[ Options ] Modify options
[ Quit ] Return to disk selection
Next, view the selected partition.
Partition Start End Size in sectors
> 1 P Linux filesys. data 2048 910155775 910153728 [drive2]
Then press the right arrow to select [ List ] at the bottom and press enter.
[ Type ] [Superblock] >[ List ] [Image Creation] [ Quit ]
Notice that it looks as if we’re starting in /, but this is actually the base of the file system that we’re working in. In this example, that’s /home.
Directory / <== starting point
>drwxr-xr-x 0 0 4096 23-Sep-2020 17:46 .
drwxr-xr-x 0 0 4096 23-Sep-2020 17:46 ..
drwx——— 0 0 16384 22-Sep-2020 11:30 lost+found
drwxr-xr-x 1008 1008 4096 9-Jul-2019 14:10 dorothy
drwxr-xr-x 1001 1001 4096 22-Sep-2020 12:12 nemo
drwxr-xr-x 1005 1005 4096 19-Jan-2020 11:49 eel
drwxrwxrwx 0 0 4096 25-Sep-2020 08:08 recovery
...
Next, we arrow down to the specific home directory.
drwxr-xr-x 1016 1016 4096 17-Feb-2020 16:40 gino
>drwxr-xr-x 1000 1000 20480 25-Sep-2020 08:00 shs
Press enter to move into that directory and then arrow down to a subdirectory as needed. Note that you can choose .. near the top of the list to back up if you picked the wrong one.
If you have trouble finding the file, you can press / (like when you start a search in vi) to be prompted to enter the file name or some portion of it.
Directory /shs <== current location
Previous
...
-rw-rw-r— 1000 1000 426 8-Apr-2019 19:09 2-min-topics
>-rw-rw-r— 1000 1000 24667 8-Feb-2019 08:57 Up_on_the_Roof.pdf
Once you’ve located the file that you need to restore, press “c” to select it.
NOTE: You will see helpful instructions at the bottom of your screen:
Use Left arrow to go back, Right to change directory, h to hide deleted files
q to quit, : to select the current file, a to select all files
C to copy the selected files, c to copy the current file <==
At this point, you’ll be ready to select where to restore that file within your starting directory (see earlier note about starting in a good place to check out the file before moving it back to its place of origin). In this case, the /home/recovery directory has no subdirectories, so this is our recovery spot.
NOTE: You will see helpful instructions at the bottom of the screen.
Please select a destination where /shs/Up_on_the_Roof.pdf will be copied.
Keys: Arrow keys to select another directory
C when the destination is correct
Q to quit
Directory /home/recovery <== recovery location
Once you see “Copy done! 1 ok, 0 failed” in green, you’ll know the file has been restored.
The file in this case was left in /home/recovery/shs (starting directory with the selected directory appended).
You should probably verify that the recovered file looks right before moving it back into its original location. Make sure you also restore the original owner and group since the file will be owned by root at this point.
NOTE: For many points in the file recovery process, you can use quit (q or [ Quit ]) to back up a step. You can select quit options all the way back to the first step in the process if you like or ^c to exit immediately.
Recovery training
Recovering files using testdisk is relatively painless, but somewhat complicated. It’s probably a good idea to practice recovering files before panic time sets to give yourself a chance to get comfortable with the process.
Join the Network World communities on Facebook and LinkedIn to comment on topics that are top of mind.
via: https://www.networkworld.com/article/3575524/recovering-deleted-files-on-linux-with-testdisk.html
作者：Sandra Henry-Stocker 选题：lujun9972 译者：译者ID 校对：校对者ID