# e2image

## NAME



           e2image - Save critical ext2/ext3/ext4 file system metadata to a
           file
    


## SYNOPSIS



           **e2image**[**-r** |**-Q**[**-af**]] [ **-b** _superblock_ ] [ **-B** _blocksize_ ] [ **-cnps**]
           [ **-o** _src_offset_ ] [ **-O** _dest_offset_ ] _device image-file_
           **e2image -I** _device image-file_
    


## DESCRIPTION



           The **e2image** program will save critical ext2, ext3, or ext4 file
           system metadata located on _device_ to a file specified by _image-_
           _file_.  The image file may be examined by **dumpe2fs** and **debugfs** , by
           using the **-i** option to those programs.  This can assist an expert
           in recovering catastrophically corrupted file systems.
    
           It is a very good idea to create image files for all file systems
           on a system and save the partition layout (which can be generated
           using the **fdisk -l** command) at regular intervals — at boot time,
           and/or every week or so.  The image file should be stored on some
           file system other than the file system whose data it contains, to
           ensure that this data is accessible in the case where the file
           system has been badly damaged.
    
           To save disk space, **e2image** creates the image file as a sparse
           file, or in QCOW2 format.  Hence, if the sparse image file needs
           to be copied to another location, it should either be compressed
           first or copied using the **--sparse=always** option to the GNU
           version of cp(1).  This does not apply to the QCOW2 image, which
           is not sparse.
    
           The size of an ext2 image file depends primarily on the size of
           the file systems and how many inodes are in use.  For a typical 10
           Gigabyte file system, with 200,000 inodes in use out of 1.2
           million inodes, the image file will be approximately 35 Megabytes;
           a 4 Gigabyte file system with 15,000 inodes in use out of 550,000
           inodes will result in a 3 Megabyte image file.  Image files tend
           to be quite compressible; an image file taking up 32 Megabytes of
           space on disk will generally compress down to 3 or 4 Megabytes.
    
           If _image-file_ is **-** , then the output of **e2image** will be sent to
           standard output, so that the output can be piped to another
           program, such as **gzip**(1).  (Note that this is currently only
           supported when creating a raw image file using the **-r** option,
           since the process of creating a normal image file, or QCOW2 image
           currently requires random access to the file, which cannot be done
           using a pipe.
    


## OPTIONS



           **-a** Include file data in the image file.  Normally **e2image** only
                  includes fs metadata, not regular file data.  This option
                  will produce an image that is suitable to use to clone the
                  entire FS or for backup purposes.  Note that this option
                  only works with the raw (_-r_) or QCOW2 (_-Q_) formats.  In
                  conjunction with the **-r** option it is possible to clone all
                  and only the used blocks of one file system to another
                  device/image file.
    
           **-b** _superblock_
                  Get image from partition with broken primary superblock by
                  using the superblock located at file system block number
                  _superblock_.  The partition is copied as-is including broken
                  primary superblock.
    
           **-B** _blocksize_
                  Set the file system blocksize in bytes.  Normally, **e2image**
                  will search for the superblock at various different block
                  sizes in an attempt to find the appropriate blocksize. This
                  search can be fooled in some cases.  This option forces
                  e2fsck to only try locating the superblock with a
                  particular blocksize. If the superblock is not found,
                  e2image will terminate with a fatal error.
    
           **-c** Compare each block to be copied from the source _device_ to
                  the corresponding block in the target _image-file_.  If both
                  are already the same, the write will be skipped.  This is
                  useful if the file system is being cloned to a flash-based
                  storage device (where reads are very fast and where it is
                  desirable to avoid unnecessary writes to reduce write wear
                  on the device).
    
           **-f** Override the read-only requirement for the source file
                  system when saving the image file using the **-r** and **-Q**
                  options.  Normally, if the source file system is in use,
                  the resulting image file is very likely not going to be
                  useful. In some cases where the source file system is in
                  constant use this may be better than no image at all.
    
           **-I** install the metadata stored in the image file back to the
                  device.  It can be used to restore the file system metadata
                  back to the device in emergency situations.
    
           **WARNING!!!!** The **-I** option should only be used as a desperation
           measure when other alternatives have failed.  If the file system
           has changed since the image file was created, data **will** be lost.
           In general, you should make another full image backup of the file
           system first, in case you wish to try other recovery strategies
           afterward.
    
           **-n** Cause all image writes to be skipped, and instead only
                  print the block numbers that would have been written.
    
           **-o** _src_offset_
                  Specify offset of the image to be read from the start of
                  the source _device_ in bytes.  See **OFFSETS** for more details.
    
           **-O** _tgt_offset_
                  Specify offset of the image to be written from the start of
                  the target _image-file_ in bytes.  See **OFFSETS** for more
                  details.
    
           **-p** Show progress of image-file creation.
    
           **-Q** Create a QCOW2-format image file instead of a normal image
                  file, suitable for use by virtual machine images, and other
                  tools that can use the **.qcow** image format. See **QCOW2 IMAGE**
                  **FILES** below for details.
    
           **-r** Create a raw image file instead of a normal image file.
                  See **RAW IMAGE FILES** below for details.
    
           **-s** Scramble directory entries and zero out unused portions of
                  the directory blocks in the written image file to avoid
                  revealing information about the contents of the file
                  system.  However, this will prevent analysis of problems
                  related to hash-tree indexed directories.
    


## RAW IMAGE FILES



           The **-r** option will create a raw image file, which differs from a
           normal image file in two ways.  First, the file system metadata is
           placed in the same relative offset within _image-file_ as it is in
           the _device_ so that debugfs(8), dumpe2fs(8), e2fsck(8), losetup(8),
           etc. can be run directly on the raw image file.  In order to
           minimize the amount of disk space consumed by the raw image file,
           it is created as a sparse file.  (Beware of copying or
           compressing/decompressing this file with utilities that don't
           understand how to create sparse files; the file will become as
           large as the file system itself!)  Secondly, the raw image file
           also includes indirect blocks and directory blocks, which the
           standard image file does not have.
    
           Raw image files are sometimes used when sending file systems to
           the maintainer as part of bug reports to e2fsprogs.  When used in
           this capacity, the recommended command is as follows (replace **hda1**
           with the appropriate device for your system):
    
                **e2image -r /dev/hda1 - | bzip2 > hda1.e2i.bz2**
    
           This will only send the metadata information, without any data
           blocks.  However, the filenames in the directory blocks can still
           reveal information about the contents of the file system that the
           bug reporter may wish to keep confidential.  To address this
           concern, the **-s** option can be specified to scramble the filenames
           in the image.
    
           Note that this will work even if you substitute **/dev/hda1** for
           another raw disk image, or QCOW2 image previously created by
           **e2image**.
    


## QCOW2 IMAGE FILES



           The **-Q** option will create a QCOW2 image file instead of a normal,
           or raw image file.  A QCOW2 image contains all the information the
           raw image does, however unlike the raw image it is not sparse. The
           QCOW2 image minimize the amount of space used by the image by
           storing it in special format which packs data closely together,
           hence avoiding holes while still minimizing size.
    
           In order to send file system to the maintainer as a part of bug
           report to e2fsprogs, use following commands (replace **hda1** with the
           appropriate device for your system):
    
                **e2image -Q /dev/hda1 hda1.qcow2**
                **bzip2 -z hda1.qcow2**
    
           This will only send the metadata information, without any data
           blocks.  As described for **RAW IMAGE FILES** the **-s** option can be
           specified to scramble the file system names in the image.
    
           Note that the QCOW2 image created by **e2image** is a regular QCOW2
           image and can be processed by tools aware of QCOW2 format such as
           for example **qemu-img**.
    
           You can convert a .qcow2 image into a raw image with:
    
                **e2image -r hda1.qcow2 hda1.raw**
    
           This can be useful to write a QCOW2 image containing all data to a
           sparse image file where it can be loop mounted, or to a disk
           partition.  Note that this may not work with QCOW2 images not
           generated by e2image.
    


## OFFSETS



           Normally a file system starts at the beginning of a partition, and
           **e2image** is run on the partition.  When working with image files,
           you don't have the option of using the partition device, so you
           can specify the offset where the file system starts directly with
           the **-o** option.  Similarly the **-O** option specifies the offset that
           should be seeked to in the destination before writing the file
           system.
    
           For example, if you have a **dd** image of a whole hard drive that
           contains an ext2 fs in a partition starting at 1 MiB, you can
           clone that image to a block device with:
    
                **e2image -aro 1048576 img /dev/sda1**
    
           Or you can clone a file system from a block device into an image
           file, leaving room in the first MiB for a partition table with:
    
                **e2image -arO 1048576 /dev/sda1 img**
    
           If you specify at least one offset, and only one file, an in-place
           move will be performed, allowing you to safely move the file
           system from one offset to another.
    


## AVAILABILITY



           **e2image** is part of the e2fsprogs package and is available from
           http://e2fsprogs.sourceforge.net.
    


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