.SH SYNOPSIS
.B e2image
[
-.B \-rsIQa
+.B \-r|\-Q
]
+[
+.B \-f
+]
+[
+.B \-b
+.I superblock
+]
+[
+.B \-B
+.I blocksize
+]
+.I device
+.I image-file
+.br
+.B e2image
+.B \-I
.I device
.I image-file
+.br
+.B e2image
+.B \-ra
+[
+.B \-cfnp
+]
+[
+.B \-o
+.I src_offset
+]
+[
+.B \-O
+.I dest_offset
+]
+.I src_fs
+[
+.I dest_fs
+]
.SH DESCRIPTION
The
.B e2image
e2fsck will be enhanced to be able to use the image file to help
recover a badly damaged filesystem.
.PP
+When saving an e2image for debugging purposes, using either the
+.B \-r
+or
+.B \-Q
+options, the filesystem must be unmounted or be mounted read/only, in order
+for the image file to be in a consistent state. This requirement can be
+overridden using the
+.B \-f
+option, but the resulting image file is very likely not going to be useful.
+.PP
If
.I image-file
is \-, then the output of
option will prevent analysis of problems related to hash-tree indexed
directories.
.PP
+Option
+.B \-b
+.I superblock
+can be used to get image from partition with broken primary superblock.
+The partition is copied as-is including broken primary superblock.
+.PP
+Option
+.B \-B
+.I blocksize
+can be used to set superblock block size. Normally, e2fsck 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 at a particular
+blocksize. If the superblock is not found, e2fsck will terminate with a
+fatal error.
+.PP
Note that this will work even if you substitute "/dev/hda1" for another raw
disk image, or QCOW2 image previously created by
.BR e2image .
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.
.PP
+Options
+.B \-b
+.I superblock
+and
+.B \-B
+.I blocksize
+can be used same way as for raw images.
+.PP
.SH INCLUDING DATA
Normally
.B e2image
only includes fs metadata, not regular file data. The
.B \-a
option can be specified to include all data. This will
-give an image that is suitible to use to clone the entire FS or
+give 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 or QCOW2 formats.
+raw or QCOW2 formats. The
+.B \-p
+switch may be given to show progress. 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), the
+.B \-c
+option which cause e2image to try reading a block from the destination
+to see if it is identical to the block which
+.B e2image
+is about to copy. If the block is already the same, the write can be
+skipped. The
+.B \-n
+option will cause all of the writes to be no-ops, and print the blocks
+that would have been written.
+.PP
+.SH OFFSETS
+Normally a filesystem starts at the beginning of a partition, and
+.B 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 filesystem starts directly with the
+.B \-o
+option. Similarly the
+.B \-O
+option specifies the offset that should be seeked to in the destination
+before writing the filesystem.
+.PP
+For example, if you have a
+.B dd
+image of a whole hard drive that contains an ext2 fs in a partition
+starting at 1 MiB, you can clone that fs with:
+.PP
+.br
+\ \fBe2image \-aro 1048576 img /dev/sda1\fR
+.br
+.PP
+Or you can clone a fs into an image file, leaving room in the first
+MiB for a partition table with:
+.PP
+.br
+\ \fBe2image -arO 1048576 /dev/sda1 img\fR
+.br
.PP
+If you specify at least one offset, and only one file, an in-place
+move will be performed, allowing you to safely move the filesystem
+from one offset to another.
.SH AUTHOR
.B e2image
was written by Theodore Ts'o (tytso@mit.edu).
projects / thirdparty / e2fsprogs.git / blobdiff