Linux восстановить удаленный раздел

DataRecovery

Deleted or lost files can sometimes be recovered from failed or formatted drives and partitions, CD-ROMs and memory cards using the free/libre software available in the Ubuntu repositories. The data is recoverable because the information is not immediately removed from the disk. Follow these steps to recover lost data.

CAUTION

You should NOT write to the failed device, as it can worsen a hardware failure, and overwrite existant data in case of lost files .

Shut down the affected machine as soon as possible, and restart it from a LiveCD or LiveUSB. Be certain that the «live» cd does not automatically mount any partition or swap space.

Guidelines

The following software will passively try to recover your data from failed or failing hardware. If your data is not replaceable, do not attempt to write to the failed device if the following applications do not work but seek professional advice instead.

If your device is damaged, it is advisable to image the device and work on the image file for data recovery. (See below.) If hardware failure is not the problem, you can recover data directly from the device.

To recover data from a failed device, you will need another device of equal or greater storage onto which to save your data. If you need to make an image of the failed device, you will need yet another quantity of space. You should run these tools from another OS which resides on another disk or a «live» CD.

An Ubuntu Desktop CD will work fine. If you do not have a lot of ram, or do not have an internet connection on the failed computer, you can use SystemRescueCd, a live cd data recovery toolkit. It includes most of the software mentioned in this page.

[More info needed here: Is this page covering two separate scenarios: one for lost partitions, and one for damaged or deleted files? Or are the techniques described for damaged or deleted files ALSO needed if a partition has been inadvertently lost? If they are separate scenarios, it would be good to say that here.]

Lost Partition

If you made a mistake while partitioning and the partition no longer appears in the partition table, so long as you have not written data in that space, all your data is still there.

GNU Parted

Run Parted from the command line to recover your partition.

When changing the partition table on your hard drive, you must ensure that no partition on the disk is mounted. This includes swap space. The easiest way to accomplish this is to run the live cd. Parted is installed on the base Ubuntu system. Once at the desktop, open a terminal and run_:

Next run parted and tell it to use the device in question. For example, if your /dev/sda drive is the drive from which you want to recover, run:

Then, use the rescue option:

where Start is the area of the disk where you believe the partition began and END is its end. If parted finds a potential partition, it will ask you if you want to add it to the partition table.

Testdisk

Alternatively, the testdisk application may recover your partition. Use any method to install the testdisk package.

Run testdisk and it will scan your computer for media and offer you a menu-driven way to recover your partition.

Gpart

Another program that can scan drives and re-create a partition table based on «guesses» is Gpart. Use any method to install the package gpart.

To scan the first hard disk using default settings type

depending on your Ubuntu version.

You can restore the «guessed» partition table, only after checking it very carefully (you’re strongly advised to write to another device instead), using

sudo gpart -W /dev/sda /dev/sda

Imaging a damaged device, filesystem or drive

Software choices

• GNU ddrescue (packaged as gddrescue, though once installed the command is «ddrescue»)
  • This is the one you want. This documentation currently only applies to GNU ddrescue.
  • This is an older, slower shell script that needs to be run in combination with another script to do the same thing as the GNU version.

  GNU ddrescue is a data recovery tool. It copies data from one file or block device (hard disc, cdrom, etc) to another, trying hard to rescue data in case of read errors.

  Ddrescue does not truncate the output file if not asked to. So, every time you run it on the same output file, using a logfile, it tries to fill in the gaps.

  The basic operation of ddrescue is fully automatic. That is, you don’t have to wait for an error, stop the program, read the log, run it in reverse mode, etc.

  If you use the logfile feature of ddrescue, the data is rescued very efficiently (only the needed blocks are read). Also you can interrupt the rescue at any time and resume it later at the same point.

  Automatic merging of backups: If you have two or more damaged copies of a file, cdrom, etc, and run ddrescue on all of them, one at a time, with the same output file, you will probably obtain a complete and error-free file. This is so because the probability of having damaged areas at the same places on different input files is very low. Using the logfile, only the needed blocks are read from the second and successive copies.

  If the filesystem you are imaging is greater than 4 gigs in size, you will not be able to use an MSDOS (VFAT) filesystem (usually found on USB drives) to store the image, since there is a 4G limit to the maximum size of a file on such filesystems. Use EXT3 or another filesystem that can handle such file sizes.

  Use any method to install the following package:

  Run gnuddrescue like this:

  ddrescue [options] infile outfile [logfile]

  So, if /dev/sda is unreadable, you will need to acquire another disk (or other media) onto which to save the output image. You will need to have more room on the new media than on the failed disk.

  sudo ddrescue -r 3 /dev/sda /media/usbdrive/image /media/usbdrive/logfile

  Run successive passes like this:

  sudo ddrescue -r 3 -C /dev/sda /media/usbdrive/image /media/usbdrive/logfile

  and gnuddrescue will use the log file to only read the gaps with errors. In both cases, the -r option determines the number of times gddrescue will try to read when it encounters an error (-1 = infinity).

  These two examples are taken directly from the ddrescue info pages.

  Example 1: Rescue an ext2 partition in /dev/hda2 to /dev/hdb2

  ddrescue -r3 /dev/hda2 /dev/hdb2 logfile e2fsck -v -f /dev/hdb2 mount -t ext2 -o ro /dev/hdb2 /mnt

  Example 2: Rescue a CD-ROM in /dev/cdrom

  ddrescue -b 2048 /dev/cdrom cdimage logfile

  write cdimage to a blank CD-ROM

  Ran out of space while imaging the drive?

  Using Gnu ddrescue with a log file, you can continue imaging to another drive and then span the images. In this example, you have imaged some of the drive to a file on one drive, and the rest of the drive to a file on another drive. Here is how you put the pieces together:

  sudo losetup /dev/loop1 /media/Drive1/image sudo losetup /dev/loop2 /media/Drive2/image sudo mdadm -B /dev/md0 -l linear -n 2 /dev/loop1 /dev/loop2

  Your complete image fill be found at /dev/md0.

  And then to take the array down:

  sudo mdadm -S /dev/md0 sudo losetup -d /dev/loop1 sudo losetup -d /dev/loop2

  An separate disk space concern is that /var/log/kern.log and /var/log/syslog can become extremely large due to frequent I/O errors. For a severely problematic drive, it may be necessary replace these logs with links to /dev/null during use of ddrescue to avoid the / filesystem from becoming full.

  Extract filesystem from recovered image

  Now that the drive has been imaged, you can recover the filesystem from the image. If the filesystem is not recoverable, you can try to recover individual files.

  Mounting partitions on the image

  If you imaged the whole drive, you can mount the individual partitions on the image by using the «offset» option when mounting a loop filesystem. The Sleuth Kit can help.

  Use any method to install the following package:

  mmls can show you the partitions found within an image:

  $ mmls file -b DOS Partition Table Offset Sector: 0 Units are in 512-byte sectors Slot Start End Length Size Description 00: ----- 0000000000 0000000000 0000000001 0512B Primary Table (#0) 01: ----- 0000000001 0000000031 0000000031 0015K Unallocated 02: 00:01 0000000032 0001646591 0001646560 0803M DOS FAT16 (0x06) 03: 00:00 0001646592 0002013183 0000366592 0179M DOS FAT16 (0x06)

  This shows several partitions. In this example, we want to mount the DOS partition starting at block 32. To calculate the number of bytes, multiply by 512:

  $ bc bc 1.06 Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. 32 * 512 16384 quit

  sudo mount -o loop,offset=16384 file mnt

  (32 multiplied by 512 byte blocks = 16384)

  For mounting a typical NTFS partition created by Windows use:

  sudo mount -t ntfs -o r,force,loop,offset=32256 file mnt

  (63 multiplied by 512 byte blocks = 32256)

  Extract individual files from recovered image

  Foremost

  Foremost is a command-line tool which can recover files from a number of filesystems, including fat, ext3 and NTFS. It can be installed and run from the live cd.

  Boot from the live cd and then enable the universe repository and install foremost:

  Use any method to install the following package:

  Foremost can recover files from an image of the drive, or from the drive directly. If the drive has suffered hardware problems, use gnuddrescue to image the drive first.

  Assuming the lost files are on hda, you need to create a writeable directory on another drive where you can put the recovered files (lets say you have a big external usb drive (sdb)

  sudo mount /dev/sdb1 /recovery sudo mkdir /recovery/foremost

  sudo foremost -i /dev/hda -o /recovery/foremost

  To run formost on an image, just substitute the filename for the device

  sudo foremost -i image -o /recovery/foremost

  The recovered files will then be owned by root. Change their ownership so that you can use them:

  sudo chown -R youruser:youruser /recovery/foremost

  Use the -w switch to obtain only an audit of recoverable files:

  sudo foremost -w -i /dev/hda -o /recovery/foremost

  To recover only specific file types, use the -t switch:

  sudo foremost -t jpg -i /dev/hda -o /recovery/foremost

  Источник

  Kак восстановить раздел жесткого диска?

  Недавно я проводил некоторые эксперименты по подключению раздела с ext4 в Windows, и уж не знаю, как я умудрился, но удалил раздел на внешнем HDD. Со мной уже такое случалось на заре моего изучения Linux, но вот я случайно повторил опять эту ошибку, хоть и при других обстоятельствах.

  У меня уже получалось раньше восстанавливать удаленный раздел и теперь я хочу вспомнить свой старый опыт.

  Kак восстановить раздел жесткого диска самому?

  Для восстановления раздела будем использовать конечно Linux и программу testdisk. Установим её:

  После этого подключаем наш удалённый раздел (если это внешний жёсткий диск) и запускаем программу в терминале. Да-да, программа работает только через терминал, но не стоит этого боятся, так как всё достаточно просто, следите за ручками… Итак, запускаем.

  

  Выбираем первый пункт Create и жмём Enter:

  

  Как видите, программа показала нам все подключенные разделы: первые два раздела — это жёсткий диск на моём ноутбуке, второй — это внешний жёсткий диск, который мне нужно восстановить. Но вот какой из них какой, я пока не знаю, так как они оба у меня одинакового размера.

  Я не стал искушать судьбу в терминале, а просто открыл менеджер разделов gparted и в графике посмотрел, какой жёсткий диск на какой «букве».

  

  Теперь вполне очевидно, что удалённый раздел — это раздел sdb. Выбираем его в testdisk и жмём Enter.

  

  Тут нам предлагают выбрать тип таблицы на нашем жёстком диске. Выбираем первый пункт — Intel и жмём Enter. (Если у вас конечно не MAC и не Xbox)

  

  Вот тут посложнее. Примерно всё понятно, не совсем понятно, что нужно выбрать в моей ситуации? Выберу первый пункт, думаю не ошибусь.

  После нажатия программа показала, что раздела тут нет. Ну и понятно, я же его удалил. Нажал «выйти из поиска» и программа меня спросила о восстановлении, кажется. Я нажал Y и программа выдала мне мой удалённый раздел.

  

  Теперь программа предлагает разные действия, которые возможно мне нужны, но я просто жму Enter — продолжить!

  

  Тут мы переходим на пункт Write и жмём Enter. Программа спросит: типа вы уверены? Вводим Y и жмём Enter. Всё, прошла секунда и таблица разделов на месте и жёсткий диск восстановлен. Ура!

  Как видите, всё достаточно просто, и не нужно боятся этого терминала, он может стать хорошим другом, если его получше узнать!

  Источник